Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out. The
first time it did it I had started the truck, pulled out onto the
street and immediately hit a red light. While at the light I put it
in neutral and gave it enough gas to rev up the engine to 1500 rpm to
run the compressor enough to get more cooling in the 100 degree heat.
After less then a minute of waiting at the light there was a
grunge/screech/smoke/smell and no more cooling. Seemed like the
compressor had locked, oil blew, fan belt screeched over the locked
pulley and the oil burned on the exhaust manifold. Then it unlocked
but no more cooling. Upon tearing it down there was the expected
"black death" look to the oil, it had about 100K miles on the system,
and metal bits at the orifice tube screen. When I took the compressor
apart there were broken bits and obvious new wear marks on the
internals. I got a new compressor, accumulator, orifice tube and
condenser and flushed the evap and all lines. Put it back together
and it ran fine for 4 years.

Then last month I started it up after it sat all day, about a 95
degree day. Started it and just let it idle for no more then 1 to 2
minutes while I arranged my stuff before leaving. Then
grunge/screech/smoke/smell and no more cooling - same thing again but
I hadn't even sped up the engine. Immediately turned it off. Got
out and looked, oil blown out all over the engine again. Turned it
back on and the compressor spun freely, no funny noises, but no
cooling. Unlike the first time, when I tore it down I didn't find
anything much in the system, no little metal chunks, just a little bit
of "blackness" to the oil, a small amount of sludge on the O-tube
screen. The inside of the compressor did not seem to have any broken
parts. From how everything looked I might have been able to fix it
by simply recharging it but I had already ripped the compressor apart.
So I bought all new parts again and redid it last week. Got a
compressor, accumulator, o-tube and condenser from rockauto for $220.
Now it's cooling fine.

Then about 3 days after fixing it I was at the SAME park where it had
blown the second time. Started it up and heard what I thought sounded
like the grudge noise - like the fan belt was just starting to slip
and was fighting it. After having heard this twice before I
immediately turned it off. Thought maybe, just maybe I smelled a tiny
bit of burning oil but there was no smoke like the first two times.
Drove about 3 miles to the store with the AC off and a frown on my
face. Popped the hood and disconnected the compressor. Then started
the engine and turned the ac on. Then plugged the compressor back in
while I watched under the hood. Compressor came on, no funny noises,
and it started to cool!! In fact, it seemed to be working perfectly
normally. So I presume I caught it JUST in time before it blew out
the high pressure blow-off again and spewed oil everywhere.

So at this point my thinking was that maybe I was putting too much oil
in the system and slugging the compressor on start up. So I pulled
the one week old compressor back off and checked the oil level. It
was actually on the low side, certainly not at all overfilled. So put
it back together and it's working just fine.

Sorry for the long post, ...

why is this system blowing up within 1 or 2 minutes after a "cold"
start???? It's always in the 1 or 2 minutes when I would think the
system isn't even working hard yet.

Every time I start the engine (and AC) now I have my finger ready on
the AC on-off button ready to shut it off if I hear the slightest
funny noise.

I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

Ashton Crusher wrote:
I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

Clogged expansion tube. Clogged evaporator.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

On 15 Oct 2015 20:59:46 -0400, (Scott Dorsey) wrote:

Ashton Crusher wrote:
I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

Clogged expansion tube. Clogged evaporator.
--scott

Evap was not clogged either time. Doesn't have an expansion tube,
just an orifice tube. I guess that could clog but there is a filter
screen before anything gets to it. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out.
....

Black gunk may be contamination... or due to compressor failure.
Will assume the oil was correct type.
First occasion could be due to not enough cleaning and purging.
2nd and almost 3rd, not likely.
Were the oem hoses changed out for 134a hoses?

Ashton,

.. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

You have very little data so concluding that it's a "starting" phenomenon
may not be correct. You may be jumping to a conclusion.

Dave M.

On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction side?

I think the reffigerent is supposed to be only vapor by the time it goes around and come back to the input? Is that what the accumulator is for, to prevent liquid from entering the compressor?

Mark

On Thursday, October 15, 2015 at 7:55:38 PM UTC-5, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out. The
first time it did it I had started the truck, pulled out onto the
street and immediately hit a red light. While at the light I put it
in neutral and gave it enough gas to rev up the engine to 1500 rpm to
run the compressor enough to get more cooling in the 100 degree heat.
After less then a minute of waiting at the light there was a
grunge/screech/smoke/smell and no more cooling. Seemed like the
compressor had locked, oil blew, fan belt screeched over the locked
pulley and the oil burned on the exhaust manifold. Then it unlocked
but no more cooling. Upon tearing it down there was the expected
"black death" look to the oil, it had about 100K miles on the system,
and metal bits at the orifice tube screen. When I took the compressor
apart there were broken bits and obvious new wear marks on the
internals. I got a new compressor, accumulator, orifice tube and
condenser and flushed the evap and all lines. Put it back together
and it ran fine for 4 years.

Then last month I started it up after it sat all day, about a 95
degree day. Started it and just let it idle for no more then 1 to 2
minutes while I arranged my stuff before leaving. Then
grunge/screech/smoke/smell and no more cooling - same thing again but
I hadn't even sped up the engine. Immediately turned it off. Got
out and looked, oil blown out all over the engine again. Turned it
back on and the compressor spun freely, no funny noises, but no
cooling. Unlike the first time, when I tore it down I didn't find
anything much in the system, no little metal chunks, just a little bit
of "blackness" to the oil, a small amount of sludge on the O-tube
screen. The inside of the compressor did not seem to have any broken
parts. From how everything looked I might have been able to fix it
by simply recharging it but I had already ripped the compressor apart.
So I bought all new parts again and redid it last week. Got a
compressor, accumulator, o-tube and condenser from rockauto for $220.
Now it's cooling fine.

Then about 3 days after fixing it I was at the SAME park where it had
blown the second time. Started it up and heard what I thought sounded
like the grudge noise - like the fan belt was just starting to slip
and was fighting it. After having heard this twice before I
immediately turned it off. Thought maybe, just maybe I smelled a tiny
bit of burning oil but there was no smoke like the first two times.
Drove about 3 miles to the store with the AC off and a frown on my
face. Popped the hood and disconnected the compressor. Then started
the engine and turned the ac on. Then plugged the compressor back in
while I watched under the hood. Compressor came on, no funny noises,
and it started to cool!! In fact, it seemed to be working perfectly
normally. So I presume I caught it JUST in time before it blew out
the high pressure blow-off again and spewed oil everywhere.

So at this point my thinking was that maybe I was putting too much oil
in the system and slugging the compressor on start up. So I pulled
the one week old compressor back off and checked the oil level. It
was actually on the low side, certainly not at all overfilled. So put
it back together and it's working just fine.

Sorry for the long post, ...

why is this system blowing up within 1 or 2 minutes after a "cold"
start???? It's always in the 1 or 2 minutes when I would think the
system isn't even working hard yet.

Every time I start the engine (and AC) now I have my finger ready on
the AC on-off button ready to shut it off if I hear the slightest
funny noise.

I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

Whenever I've had a system that failed like yours, I used a system flush and nitrogen to completely clean out the inside of the evaporator, condenser and lines. One thing you may check is whether or not the evaporator fins are clear and unobstructed because lack of airflow through the evaporator can cause liquid refrigerant to return to the compressor and damage it. One thing to look out for in any vehicle is the fact the air inlet to the heater/AC from the floor can suck up paper and other debris from the floor and become clogged. If the evaporator doesn't have full air flow, the refrigerant can't absorb heat and flash into gas thus returning to the compressor as liquid. Oh yea, if you tear one down, always replace the accumulator/filter dryer(which can get oil logged), make sure you have the correct orifice tube if it has one, the correct amount of the right kind of oil and pull a deep vacuum before adding refrigerant. There are some new automotive refrigerants like Enviro-Safe that don't recommend evacuating the system but I've never used them. ^_^

[8~{} Uncle AC Monster

On Thu, 15 Oct 2015 17:55:20 -0700, Ashton Crusher
wrote:

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

SWAG: How tight is the belt; can it to be causing stress/binding on
the compressor clutch parts, an O-ring breaks down in the unit. Then
cooties get in the system? I have no clue.

I agree with the post to avoid a rebuilt compressor vs new.

Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck.

SNIP

Put it back together and it ran fine for 4 years.

Then last month I started it up after it sat all day, about a 95
degree day. Started it and just let it idle for no more then 1 to 2
minutes while I arranged my stuff before leaving.

SNIP

Got a compressor, accumulator, o-tube and condenser from rockauto for $220.
Now it's cooling fine.

Then about 3 days after fixing it I was at the SAME park where it had
blown the second time.

SNIP

So I presume I caught it JUST in time before it blew out
the high pressure blow-off again and spewed oil everywhere.

So at this point my thinking was that maybe I was putting too much oil
in the system and slugging the compressor on start up. So I pulled
the one week old compressor back off and checked the oil level. It
was actually on the low side, certainly not at all overfilled. So put
it back together and it's working just fine.

Sorry for the long post, ...

why is this system blowing up within 1 or 2 minutes after a "cold"
start???? It's always in the 1 or 2 minutes when I would think the
system isn't even working hard yet.

Every time I start the engine (and AC) now I have my finger ready on
the AC on-off button ready to shut it off if I hear the slightest
funny noise.

I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?


When did you do the 134A swap? After the first pop or the second?
What oil are you using?
Were ALL of the NEW parts shipped empty of oil?

If you are seeing 325 psi on the high side you have a problem. It sounds
like a restriction on the high side. Possibly a chunk of crud that
didn't get flushed out of the line.


--
Steve W.

On Fri, 16 Oct 2015 08:51:21 -0400, "David L. Martel"
wrote:

Ashton,

. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

You have very little data so concluding that it's a "starting" phenomenon
may not be correct. You may be jumping to a conclusion.

Dave M.

There is little data but all three times it was immediately after
starting while idling. To me that would seem like the easiest part of
the work day for the AC yet it overpressureized and "blew". I keep
trying to figure out what there would be about the "refrigeration
cycle" that would somehow create such a high pressure within a couple
minutes of system startup. To blow off the high pressure valve it has
to get to something like 400+ psi. Even with it sitting in the
driveway as I finish putting 134a in it in 95 degree temps it only got
to around 325 psi at 2500 rpm. At idle it's in the 200's. The only
things I can see that would make it blow are a blockage or oil or
freon slugging. I can see how a blockage could happen but if there is
stuff in there that's going to block something it seems like it would
have happened at high speed "the day before", not "today" when the
system is just loafing along at low rpm's. Is there something about
startup that would create an oil or refrigerant slug in the
compressor?

On Thu, 15 Oct 2015 21:36:46 -0500, Paul in Houston TX
wrote:

Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out.
...

Black gunk may be contamination... or due to compressor failure.
Will assume the oil was correct type.
First occasion could be due to not enough cleaning and purging.
2nd and almost 3rd, not likely.
Were the oem hoses changed out for 134a hoses?


I know one of them was as it had a muffler in it when it blew up 4
years ago and I had an AC shop redo the manifold with a new hose to
replace the part with the muffler. It's possible the other hose on
the manifold is an 18 year old one. From what I've read there is not
supposed to be any problem with old hoses that have been well soaked
with oil. But those two short sections are the only hose, the rest is
pipe.

On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction side?

I think the reffigerent is supposed to be only vapor by the time it goes around and come back to the input? Is that what the accumulator is for, to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

On Fri, 16 Oct 2015 11:16:04 -0700, Oren wrote:

On Thu, 15 Oct 2015 17:55:20 -0700, Ashton Crusher
wrote:

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?

SWAG: How tight is the belt; can it to be causing stress/binding on
the compressor clutch parts, an O-ring breaks down in the unit. Then
cooties get in the system? I have no clue.

I agree with the post to avoid a rebuilt compressor vs new.

Serpentine belt. It's as tight as the belt tensioner makes it. So
presumably no tighter then it should be but potentially loser due to
the spring weakening. All the compressors were new. The only parts
not new were the evaporator and two short pieces of hose. The hoses
and evap were easily blown thru for flushing.

On Fri, 16 Oct 2015 20:42:35 -0400, "Steve W."
wrote:

Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck.

SNIP

Put it back together and it ran fine for 4 years.

Then last month I started it up after it sat all day, about a 95
degree day. Started it and just let it idle for no more then 1 to 2
minutes while I arranged my stuff before leaving.

SNIP

Got a compressor, accumulator, o-tube and condenser from rockauto for $220.
Now it's cooling fine.

Then about 3 days after fixing it I was at the SAME park where it had
blown the second time.

SNIP

So I presume I caught it JUST in time before it blew out
the high pressure blow-off again and spewed oil everywhere.

So at this point my thinking was that maybe I was putting too much oil
in the system and slugging the compressor on start up. So I pulled
the one week old compressor back off and checked the oil level. It
was actually on the low side, certainly not at all overfilled. So put
it back together and it's working just fine.

Sorry for the long post, ...

why is this system blowing up within 1 or 2 minutes after a "cold"
start???? It's always in the 1 or 2 minutes when I would think the
system isn't even working hard yet.

Every time I start the engine (and AC) now I have my finger ready on
the AC on-off button ready to shut it off if I hear the slightest
funny noise.

I put in 80% of the amount of R12 as I'm using 134a. Running it in
the driveway at 2000 rpm I've seen the low side drop to 30 and the
high side go to over 325. I don't see how they could possibly go even
that high, much less to the 400 psi needed to pop the high pressure
valve within 2 minutes after starting with the engine at or near idle
speed.

Anyone got any theories? Too much oil? Too much refrigerant? Not
enough virgins being sacrificed?


When did you do the 134A swap? After the first pop or the second?
What oil are you using?
Were ALL of the NEW parts shipped empty of oil?

If you are seeing 325 psi on the high side you have a problem. It sounds
like a restriction on the high side. Possibly a chunk of crud that
didn't get flushed out of the line.

The 134a is what I used this last time. Time before that I used a
"drop-in", ES12a that I have used in two other systems with no
problems. But to eliminate the ES12a as a potential cause I went with
the 134a this time. Yes, everything was dry except for the
compressor. It supposedly had 7 oz (the full amount for the whole
system) in it. I drained it to check and only got 5 oz out. So that
left me with the question, did they only really put 5 oz in or is
there 2oz trapped in the compressor. I went with the idea that 2 oz
were trapped for determining how much to put in the system.

The 325 reading was in 95 degree outside temperature with the vehicle
not moving, no extra fans, just the engine driven radiator fan, and at
2000 rpm. At idle speed it dropped to around 225. Will a restriction
in the high side also cause the low side readings to be high? They
were at about 30 when the high was at 325.

"Ashton Crusher" wrote in message
...

On Fri, 16 Oct 2015 08:51:21 -0400, "David L. Martel"
wrote:

Ashton,

. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

You have very little data so concluding that it's a "starting"
phenomenon
may not be correct. You may be jumping to a conclusion.

Dave M.

There is little data but all three times it was immediately after
starting while idling. To me that would seem like the easiest part of
the work day for the AC yet it overpressureized and "blew". I keep
trying to figure out what there would be about the "refrigeration
cycle" that would somehow create such a high pressure within a couple
minutes of system startup. To blow off the high pressure valve it has
to get to something like 400+ psi. Even with it sitting in the
driveway as I finish putting 134a in it in 95 degree temps it only got
to around 325 psi at 2500 rpm. At idle it's in the 200's. The only
things I can see that would make it blow are a blockage or oil or
freon slugging. I can see how a blockage could happen but if there is
stuff in there that's going to block something it seems like it would
have happened at high speed "the day before", not "today" when the
system is just loafing along at low rpm's. Is there something about
startup that would create an oil or refrigerant slug in the
compressor?


What size of Vehicle or what make dose it utilize Expansion vale.
dose it use electric fan motor, is it Mechanical directly hook up to motor.
when Refrigerant was lost, did you find the leak is it on high side or low
side.
Have you Evacuated system before you added Refrigerant..
How much of refrigerant did you use, all systems are not same size.
If your Vehicle is older then 1992 which means it is design for R-12
and not R-134, Sorry but that is the way it is!

On Sun, 18 Oct 2015 12:44:29 -0700, "tony944" wrote:



"Ashton Crusher" wrote in message
.. .

On Fri, 16 Oct 2015 08:51:21 -0400, "David L. Martel"
wrote:

Ashton,

. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

You have very little data so concluding that it's a "starting"
phenomenon
may not be correct. You may be jumping to a conclusion.

Dave M.

There is little data but all three times it was immediately after
starting while idling. To me that would seem like the easiest part of
the work day for the AC yet it overpressureized and "blew". I keep
trying to figure out what there would be about the "refrigeration
cycle" that would somehow create such a high pressure within a couple
minutes of system startup. To blow off the high pressure valve it has
to get to something like 400+ psi. Even with it sitting in the
driveway as I finish putting 134a in it in 95 degree temps it only got
to around 325 psi at 2500 rpm. At idle it's in the 200's. The only
things I can see that would make it blow are a blockage or oil or
freon slugging. I can see how a blockage could happen but if there is
stuff in there that's going to block something it seems like it would
have happened at high speed "the day before", not "today" when the
system is just loafing along at low rpm's. Is there something about
startup that would create an oil or refrigerant slug in the
compressor?


What size of Vehicle or what make dose it utilize Expansion vale.
dose it use electric fan motor, is it Mechanical directly hook up to motor.
when Refrigerant was lost, did you find the leak is it on high side or low
side.
Have you Evacuated system before you added Refrigerant..
How much of refrigerant did you use, all systems are not same size.
If your Vehicle is older then 1992 which means it is design for R-12
and not R-134, Sorry but that is the way it is!




The system MUST be purged before recharging, partigularly when
switching refrigerants. If it has an orifice it must be removed and
checked - preferably replaced AFTER purging the system with nitrogen.
If it is an expansion valve system I'd take a real good look at the
valve and check function. If the system has been open any length of
time , the receiver-drier should also be replaced. Then the system
should be totally evacuated and held at a deep vaccuum for at least an
hour, then the service valves should be closed and the system left for
an hour or more- check for loss of vaccuum. If the system proves to be
sound, install the r134 conversion valves on both high and low
pressure sides, Charge to the low side with the specified amount of
Ester oil. PAG is also used with 134, but on a conversion, in
particular, Ester is better as it is les hygroscopic (it has less of
an affinity for moisture). Then draw in the proper amount of R134A..
Proper fill is aproxemately 65% of the R12 charge.. A 75% charge is
USUALLY an overcharge. On systems with an orifice tube, for
conversion I REALLY prefer the automatic (AKA Smart VOV) tube. If not,
the blue Ford tube works best for 134 in a conversion (even on a
Chevy).
I installed AC on my 1996 Ford Ranger, using the hoses, compressor,
receiver and evaporator from a 1993 with the condenser for a '95. I
put in the smart VOV and charged it to 1994 R134 specs (36 oz) - and
promptly blew the overpressure plug. I then checked several other
sources and found out the published spec was WAY too high., so I used
the 1997 spec (22 oz), which ended up being just over 65% of the
1993-R12 spec. (32 oz) which would be 20.8 oz.
Ford specifies PAG oil for R134A, but I use Ester because it is
compatible with the old mineral oil - and on a conversion, there is
ALWAYS a possibility there is some mineral oil remaining in the system
- no matter how careful you are. It is also safe to mix with PAG.

PAG is NOT compatible with chlorinated refrigerants - like R12 or R22.
It will turn to thick brown mud upon contact with R12..

Perhaps that is the OP's problem??? The "mud" will plug the expansion
valve/orifice and cause the high side to go nuts.
It might allow the system to work well for a day or so before plugging
the orifice - and then blowing the system on restart.

It's been 3 summers now and it cools perfectly.

On Sun, 18 Oct 2015 17:10:20 -0400, wrote:

On Sun, 18 Oct 2015 12:44:29 -0700, "tony944" wrote:



"Ashton Crusher" wrote in message
. ..

On Fri, 16 Oct 2015 08:51:21 -0400, "David L. Martel"
wrote:

Ashton,

. Why would it do so immediately
after starting and while idling yet never do so while running down the
highway for hours on end?

You have very little data so concluding that it's a "starting"
phenomenon
may not be correct. You may be jumping to a conclusion.

Dave M.

There is little data but all three times it was immediately after
starting while idling. To me that would seem like the easiest part of
the work day for the AC yet it overpressureized and "blew". I keep
trying to figure out what there would be about the "refrigeration
cycle" that would somehow create such a high pressure within a couple
minutes of system startup. To blow off the high pressure valve it has
to get to something like 400+ psi. Even with it sitting in the
driveway as I finish putting 134a in it in 95 degree temps it only got
to around 325 psi at 2500 rpm. At idle it's in the 200's. The only
things I can see that would make it blow are a blockage or oil or
freon slugging. I can see how a blockage could happen but if there is
stuff in there that's going to block something it seems like it would
have happened at high speed "the day before", not "today" when the
system is just loafing along at low rpm's. Is there something about
startup that would create an oil or refrigerant slug in the
compressor?


What size of Vehicle or what make dose it utilize Expansion vale.
dose it use electric fan motor, is it Mechanical directly hook up to motor.
when Refrigerant was lost, did you find the leak is it on high side or low
side.
Have you Evacuated system before you added Refrigerant..
How much of refrigerant did you use, all systems are not same size.
If your Vehicle is older then 1992 which means it is design for R-12
and not R-134, Sorry but that is the way it is!




The system MUST be purged before recharging, partigularly when
switching refrigerants. If it has an orifice it must be removed and
checked - preferably replaced AFTER purging the system with nitrogen.
If it is an expansion valve system I'd take a real good look at the
valve and check function. If the system has been open any length of
time , the receiver-drier should also be replaced. Then the system
should be totally evacuated and held at a deep vaccuum for at least an
hour, then the service valves should be closed and the system left for
an hour or more- check for loss of vaccuum. If the system proves to be
sound, install the r134 conversion valves on both high and low
pressure sides, Charge to the low side with the specified amount of
Ester oil. PAG is also used with 134, but on a conversion, in
particular, Ester is better as it is les hygroscopic (it has less of
an affinity for moisture). Then draw in the proper amount of R134A..
Proper fill is aproxemately 65% of the R12 charge.. A 75% charge is
USUALLY an overcharge. On systems with an orifice tube, for
conversion I REALLY prefer the automatic (AKA Smart VOV) tube. If not,
the blue Ford tube works best for 134 in a conversion (even on a
Chevy).
I installed AC on my 1996 Ford Ranger, using the hoses, compressor,
receiver and evaporator from a 1993 with the condenser for a '95. I
put in the smart VOV and charged it to 1994 R134 specs (36 oz) - and
promptly blew the overpressure plug. I then checked several other
sources and found out the published spec was WAY too high., so I used
the 1997 spec (22 oz), which ended up being just over 65% of the
1993-R12 spec. (32 oz) which would be 20.8 oz.
Ford specifies PAG oil for R134A, but I use Ester because it is
compatible with the old mineral oil - and on a conversion, there is
ALWAYS a possibility there is some mineral oil remaining in the system
- no matter how careful you are. It is also safe to mix with PAG.

PAG is NOT compatible with chlorinated refrigerants - like R12 or R22.
It will turn to thick brown mud upon contact with R12..

Perhaps that is the OP's problem??? The "mud" will plug the expansion
valve/orifice and cause the high side to go nuts.
It might allow the system to work well for a day or so before plugging
the orifice - and then blowing the system on restart.

It's been 3 summers now and it cools perfectly.








There are almost no original parts left, the only significant one is
the evaporator. Everything's been flushed twice now since it
originally had the mineral oil. It's had PAG46 since the first redo 4
years ago.

What would nitrogen do that isn't taken care of by the flush and
pulling a vacuum?

I would like to have tried a variable orifice tube but the local AC
shop who is also a huge wholesale vender as well as custom maker of
hoses and such told me they see a lot of people who try them pull them
back out because they malfunction in some fashion. Mine is a real
pain in the behind to get to so I stuck with a fixed one.

I almost put r12 in it but I see from your post that would have not
worked at all well with the PAG. Good thing I went with the 134a.

You said the R12 to 134a conversion is 65%. Every other thing I've
read has put it somewhere between 80% to 90%. I used 85%.

Ashton Crusher wrote:
On Thu, 15 Oct 2015 21:36:46 -0500, Paul in Houston TX
wrote:

Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out.
...

Black gunk may be contamination... or due to compressor failure.
Will assume the oil was correct type.
First occasion could be due to not enough cleaning and purging.
2nd and almost 3rd, not likely.
Were the oem hoses changed out for 134a hoses?


I know one of them was as it had a muffler in it when it blew up 4
years ago and I had an AC shop redo the manifold with a new hose to
replace the part with the muffler. It's possible the other hose on
the manifold is an 18 year old one. From what I've read there is not
supposed to be any problem with old hoses that have been well soaked
with oil. But those two short sections are the only hose, the rest is
pipe.

Might want to check out this a/c pdf. It's pretty good. Scroll down to ~ page 34.
http://ecat.spectrapremium.com/bulle...p_eng_2007.pdf

On Sun, 18 Oct 2015 17:56:47 -0500, Paul in Houston TX
wrote:

Ashton Crusher wrote:
On Thu, 15 Oct 2015 21:36:46 -0500, Paul in Houston TX
wrote:

Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor. In both cases
it blew very shortly, within minutes, of starting the truck. It blew
so shortly after starting the truck I have a hard time seeing how the
pressure could be high enough to "blow" but in both cases it popped
the high pressure relief valve and spewed oil and refrigerant out.
...

Black gunk may be contamination... or due to compressor failure.
Will assume the oil was correct type.
First occasion could be due to not enough cleaning and purging.
2nd and almost 3rd, not likely.
Were the oem hoses changed out for 134a hoses?


I know one of them was as it had a muffler in it when it blew up 4
years ago and I had an AC shop redo the manifold with a new hose to
replace the part with the muffler. It's possible the other hose on
the manifold is an 18 year old one. From what I've read there is not
supposed to be any problem with old hoses that have been well soaked
with oil. But those two short sections are the only hose, the rest is
pipe.

Might want to check out this a/c pdf. It's pretty good. Scroll down to ~ page 34.
http://ecat.spectrapremium.com/bulle...p_eng_2007.pdf



Thanks, that's a really good read.

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction side?

I think the reffigerent is supposed to be only vapor by the time it goes around and come back to the input? Is that what the accumulator is for, to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is a combination of liquid and vapor. Also propnae containers are the same.


When the system has been idle, the liquid will collect in the coldest part.
If it is all at the same _exact_ temperature, I'm not sure what determines where the liquid collects.

Mark

On Wed, 21 Oct 2015 14:16:24 -0700 (PDT), wrote:

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction side?

I think the reffigerent is supposed to be only vapor by the time it goes around and come back to the input? Is that what the accumulator is for, to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is a combination of liquid and vapor. Also propnae containers are the same.


When the system has been idle, the liquid will collect in the coldest part.
If it is all at the same _exact_ temperature, I'm not sure what determines where the liquid collects.

Mark





It's not clear to me that there is any liquid when the system isn't
running. I know there is in the can but once it's in the car isn't
the volume of the system so large that it's all vapor until you start
the compressor? I'm asking, I don't know. Are you sure there is
liquid in the system when it's off? If so, that might be what's going
on, it's somehow sucking liquid in before it gets spread all over the
system.

"Ashton Crusher" wrote in message
...

On Wed, 21 Oct 2015 14:16:24 -0700 (PDT), wrote:

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke
wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction
side?

I think the reffigerent is supposed to be only vapor by the time it goes
around and come back to the input? Is that what the accumulator is for,
to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is
a combination of liquid and vapor. Also propnae containers are the same.


When the system has been idle, the liquid will collect in the coldest part.
If it is all at the same _exact_ temperature, I'm not sure what determines
where the liquid collects.

Mark





It's not clear to me that there is any liquid when the system isn't
running. I know there is in the can but once it's in the car isn't
the volume of the system so large that it's all vapor until you start
the compressor? I'm asking, I don't know. Are you sure there is
liquid in the system when it's off? If so, that might be what's going
on, it's somehow sucking liquid in before it gets spread all over the
system.

Mark is right all Refrigerant will migrate in or on coldest spot in any
system.
However it will also depend configuration of motor and setup of AC.
Some Vehicle have compressor on side of motor and some practically on
Bottom,
Bottom is critical point, if Vehicle sits for period of time not running
the refrigerant will getter at the lowest point, which in this case can be
in Compressor. Also one must be very careful how much oil is in system
and that will defiantly can do the damage. Automobile Compressor
or better with les then more oil in the system.

On Fri, 23 Oct 2015 10:13:07 -0700, "tony944" wrote:



"Ashton Crusher" wrote in message
.. .

On Wed, 21 Oct 2015 14:16:24 -0700 (PDT), wrote:

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke
wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction
side?

I think the reffigerent is supposed to be only vapor by the time it goes
around and come back to the input? Is that what the accumulator is for,
to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is
a combination of liquid and vapor. Also propnae containers are the same.


When the system has been idle, the liquid will collect in the coldest part.
If it is all at the same _exact_ temperature, I'm not sure what determines
where the liquid collects.

Mark





It's not clear to me that there is any liquid when the system isn't
running. I know there is in the can but once it's in the car isn't
the volume of the system so large that it's all vapor until you start
the compressor? I'm asking, I don't know. Are you sure there is
liquid in the system when it's off? If so, that might be what's going
on, it's somehow sucking liquid in before it gets spread all over the
system.

In a properly charged and properly functioning automotive AC system
there is no liquid in the system when at rest.
When running liquid should NEVER reach the compressor. If it does, the
system is GROSSLY overcharged (or terribly iced up). The liquid
accumulates in the reciever drier and the high pressure line from the
condenser to the expansion valve or orifice where it is "sprayed"
into the low pressure side just upstream of the evaporator, where it
turns to vapour and returns to the compressor.

Mark is right all Refrigerant will migrate in or on coldest spot in any
system.
However it will also depend configuration of motor and setup of AC.
Some Vehicle have compressor on side of motor and some practically on
Bottom,
Bottom is critical point, if Vehicle sits for period of time not running
the refrigerant will getter at the lowest point, which in this case can be
in Compressor. Also one must be very careful how much oil is in system
and that will defiantly can do the damage. Automobile Compressor
or better with les then more oil in the system.

On Friday, October 23, 2015 at 3:40:59 PM UTC-5, wrote:
On Fri, 23 Oct 2015 10:13:07 -0700, "tony944" wrote:


"Ashton Crusher" wrote in message
.. .

On Wed, 21 Oct 2015 14:16:24 -0700 (PDT), wrote:

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke
wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction
side?

I think the reffigerent is supposed to be only vapor by the time it goes
around and come back to the input? Is that what the accumulator is for,
to prevent liquid from entering the compressor?

Mark

That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is
a combination of liquid and vapor. Also propnae containers are the same.

When the system has been idle, the liquid will collect in the coldest part.
If it is all at the same _exact_ temperature, I'm not sure what determines
where the liquid collects.

Mark


It's not clear to me that there is any liquid when the system isn't
running. I know there is in the can but once it's in the car isn't
the volume of the system so large that it's all vapor until you start
the compressor? I'm asking, I don't know. Are you sure there is
liquid in the system when it's off? If so, that might be what's going
on, it's somehow sucking liquid in before it gets spread all over the
system.

In a properly charged and properly functioning automotive AC system
there is no liquid in the system when at rest.
When running liquid should NEVER reach the compressor. If it does, the
system is GROSSLY overcharged (or terribly iced up). The liquid
accumulates in the reciever drier and the high pressure line from the
condenser to the expansion valve or orifice where it is "sprayed"
into the low pressure side just upstream of the evaporator, where it
turns to vapour and returns to the compressor.

Mark is right all Refrigerant will migrate in or on coldest spot in any
system.
However it will also depend configuration of motor and setup of AC.
Some Vehicle have compressor on side of motor and some practically on
Bottom,
Bottom is critical point, if Vehicle sits for period of time not running
the refrigerant will getter at the lowest point, which in this case can be
in Compressor. Also one must be very careful how much oil is in system
and that will defiantly can do the damage. Automobile Compressor
or better with les then more oil in the system.

It depends on the design of the vehicle's AC system. My Mopars had a receiver dryer on the liquid line on the outlet of the condenser (high side) and my GM vehicles had an accumulator connected to the outlet of the evaporator (low side). Both designs worked well. ^_^

[8~{} Uncle AC Monster

wrote in message ...

On Fri, 23 Oct 2015 10:13:07 -0700, "tony944" wrote:



"Ashton Crusher" wrote in message
.. .

On Wed, 21 Oct 2015 14:16:24 -0700 (PDT), wrote:

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke
wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction
side?

I think the reffigerent is supposed to be only vapor by the time it
goes
around and come back to the input? Is that what the accumulator is
for,
to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is
a combination of liquid and vapor. Also propnae containers are the same.


When the system has been idle, the liquid will collect in the coldest
part.
If it is all at the same _exact_ temperature, I'm not sure what determines
where the liquid collects.

Mark





It's not clear to me that there is any liquid when the system isn't
running. I know there is in the can but once it's in the car isn't
the volume of the system so large that it's all vapor until you start
the compressor? I'm asking, I don't know. Are you sure there is
liquid in the system when it's off? If so, that might be what's going
on, it's somehow sucking liquid in before it gets spread all over the
system.

In a properly charged and properly functioning automotive AC system
there is no liquid in the system when at rest.

* Sir you are full of, I work on ACs GM Chrysler and Ford and are all
different and all have different capacity of refrigerant, yes some small car
may have critical charge where condenser is undersized, but not very many,
cars can run from 1# to 3,3/4# some SUVs and limo's even more capacity
and you are telling us that there is never any liquid in the system,
all I can say you are full of????*

When running liquid should NEVER reach the compressor. If it does, the
system is GROSSLY overcharged (or terribly iced up). The liquid
accumulates in the reciever drier and the high pressure line from the
condenser to the expansion valve or orifice where it is "sprayed"
into the low pressure side just upstream of the evaporator, where it
turns to vapour and returns to the compressor.

Mark is right all Refrigerant will migrate in or on coldest spot in any
system.
However it will also depend configuration of motor and setup of AC.
Some Vehicle have compressor on side of motor and some practically on
Bottom,
Bottom is critical point, if Vehicle sits for period of time not running
the refrigerant will getter at the lowest point, which in this case can be
in Compressor. Also one must be very careful how much oil is in system
and that will defiantly can do the damage. Automobile Compressor
or better with les then more oil in the system.

On Sat, 24 Oct 2015 13:50:33 -0700, "tony944" wrote:



wrote in message ...

On Fri, 23 Oct 2015 10:13:07 -0700, "tony944" wrote:



"Ashton Crusher" wrote in message
. ..

On Wed, 21 Oct 2015 14:16:24 -0700 (PDT), wrote:

On Sunday, October 18, 2015 at 2:59:23 PM UTC-4, Ashton Crusher wrote:
On Fri, 16 Oct 2015 06:45:28 -0700 (PDT), wrote:

On Friday, October 16, 2015 at 9:10:17 AM UTC-4, Colonel Edmund Burke
wrote:
On 10/15/2015 5:55 PM, Ashton Crusher wrote:
Twice now my 92 Explorer has "blown" the compressor.

I think you gots gremlins in there.

Is it possible the compressor drew liquid refrigerant into the suction
side?

I think the reffigerent is supposed to be only vapor by the time it
goes
around and come back to the input? Is that what the accumulator is
for,
to prevent liquid from entering the compressor?

Mark


That is what seems most likely to me but it also seems to me that the
least likely time for there to be liquid is on a "cold start" when
it's idling. Isn't the liquid more likely to have condensed out after
it's been running for a while at higher speeds?

It's the same as when the refrigerant is in the can when you buy it, it is
a combination of liquid and vapor. Also propnae containers are the same.


When the system has been idle, the liquid will collect in the coldest
part.
If it is all at the same _exact_ temperature, I'm not sure what determines
where the liquid collects.

Mark





It's not clear to me that there is any liquid when the system isn't
running. I know there is in the can but once it's in the car isn't
the volume of the system so large that it's all vapor until you start
the compressor? I'm asking, I don't know. Are you sure there is
liquid in the system when it's off? If so, that might be what's going
on, it's somehow sucking liquid in before it gets spread all over the
system.

In a properly charged and properly functioning automotive AC system
there is no liquid in the system when at rest.

* Sir you are full of, I work on ACs GM Chrysler and Ford and are all
different and all have different capacity of refrigerant, yes some small car
may have critical charge where condenser is undersized, but not very many,
cars can run from 1# to 3,3/4# some SUVs and limo's even more capacity
and you are telling us that there is never any liquid in the system,
all I can say you are full of????*

You are correct - there will be some liquid in the system, Generally
in the reciever/drier, but if you overcharge it and you flood the
evaporator you will get liquid into the compressor
The capacity of the system has nothing to do with it, and if liquid
EVER enters the low side of the compressor, youhave BIG problems.

When running liquid should NEVER reach the compressor. If it does, the
system is GROSSLY overcharged (or terribly iced up). The liquid
accumulates in the reciever drier and the high pressure line from the
condenser to the expansion valve or orifice where it is "sprayed"
into the low pressure side just upstream of the evaporator, where it
turns to vapour and returns to the compressor.

Mark is right all Refrigerant will migrate in or on coldest spot in any
system.
However it will also depend configuration of motor and setup of AC.
Some Vehicle have compressor on side of motor and some practically on
Bottom,
Bottom is critical point, if Vehicle sits for period of time not running
the refrigerant will getter at the lowest point, which in this case can be
in Compressor. Also one must be very careful how much oil is in system
and that will defiantly can do the damage. Automobile Compressor
or better with les then more oil in the system.

On 10/21/2015 5:16 PM, wrote:

When the system has been idle, the liquid will collect in the coldest part.
If it is all at the same _exact_ temperature, I'm not sure what determines where the liquid collects.

Mark


Might be gravity, then? Or the refrigerant
migrates towards the lubricating oil.

--
..
Christopher A. Young
learn more about Jesus
.. www.lds.org
..
..