Metalworking (rec.crafts.metalworking) Discuss various aspects of working with metal, such as machining, welding, metal joining, screwing, casting, hardening/tempering, blacksmithing/forging, spinning and hammer work, sheet metal work.

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
Old August 13th 03, 11:10 PM
jim
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

EW wrote:

My OLD 220 Volt Sears air compressor (model # 106.15378) with twin cylinders
recently quit being able to compress more than about 65 psi into the tank.
At that point, the motor still runs, the fan belt starts to squeal, and the
cylinders will no longer run. I can't even "turn" the flywheel by hand.
Lowering pressure a lot lets it run again.
I'm assuming something (reed valve??) is causing the high pressure air to
"work" against the cylinders so hard that they will simply not pump. (I
wonder if storing the compressor in my hot Texas shop -- 140 degrees in mid
PM -- contributed to this!)
Any ideas? "IF" it's a reed valve, is it accessible at the top of the
cylinder block? Is there a difference between the "input air" and output
air" reed valve? Can I fix a reed valve? ANY comments would help!!
Thanks.

EW

you have two valves in almost all compressors:
one is the load valve, after the compressor pumps up and cuts off the
machine makes a whew sound.. like air escaping for a few seconds..its a
blast... that is to take the load off the head so it can start pumping
next time when it is time for the compressor to go again....
the other valve is the check valve.... it stops the air from coming back
from the tank back to the compressor.. it holds the air back so the
motor can turn the crank...... a new check valve cost about $15.00
yours might be leaking and when getting up to 65 lbs. it will not hold
back any more??? if that is the case(when mine went bad it would blow
out the fuse for the elect. service.... was drawing about 50 amps. or
more............ is your belt tight??? do you have oil in the
compressor?? too much oil??? how about taking the larger tubing off
where it goes into the tank(the check valve is right there..where the
tubing goes into it... and run the compressor.. it will not go up in
pressure as the output of the compressor is just pumping air into the
atmosphere and not into the tank... let it run for the same amount of
time and see what happens...does it slow down??? or kill??? if not that
its the check valve... if it still slows down or kills then its the
pistons in the cylinder block that are swelling up due to friction and
you might have problems????? hope for the best... either sears or any
pump replair shop can sell you a check valve... the unloader valve at
sears is part of the whole diaphram valve that controls the pressure
from the tank.. i could not get one from sears.. you had to buy the whol
thing.. so i went to a pump repair place.. they fix air compressors and
got one there for about $15.00 also... these valve are pretty standard
sized and interchangable for most compressors... hope this helps.

  #2   Report Post  
Old August 13th 03, 11:16 PM
lcoe
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

jim wrote:
EW wrote:

My OLD 220 Volt Sears air compressor (model # 106.15378) with twin cylinders
recently quit being able to compress more than about 65 psi into the tank.
At that point, the motor still runs, the fan belt starts to squeal, and the
cylinders will no longer run. I can't even "turn" the flywheel by hand.
Lowering pressure a lot lets it run again.
I'm assuming something (reed valve??) is causing the high pressure air to
"work" against the cylinders so hard that they will simply not pump. (I
wonder if storing the compressor in my hot Texas shop -- 140 degrees in mid
PM -- contributed to this!)
Any ideas? "IF" it's a reed valve, is it accessible at the top of the
cylinder block? Is there a difference between the "input air" and output
air" reed valve? Can I fix a reed valve? ANY comments would help!!
Thanks.

EW

you have two valves in almost all compressors:

[.....]
you might have problems????? hope for the best... either sears or any
pump replair shop can sell you a check valve... the unloader valve at
sears is part of the whole diaphram valve that controls the pressure
from the tank.. i could not get one from sears.. you had to buy the whol
thing.. so i went to a pump repair place.. they fix air compressors and
got one there for about $15.00 also... these valve are pretty standard
sized and interchangable for most compressors... hope this helps.


Grainger sell unloader valve, his would cost under 10bucks for an inline.

--Loren

  #3   Report Post  
Old August 14th 03, 04:28 AM
Don Young
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

I believe your problem is caused by a broken or leaking outlet reed valve in
one cylinder. This would allow the pressure from the other cylinder to
pressurize that cylinder at the bottom of its stroke and cause excessive
pressure buildup when the piston moves up. On many compressors the reed
valves are on a plate under the head and are very easy to get to. They may
be hard or impossible to remove from the plate because the small thin heads
of the securing screws may be corroded. You may need to grind off the end of
a socket to remove any bevel. The valves and screws can be bought, perhaps
in a kit, but you may need to replace the entire plate.
Don Young
"EW" wrote in message
...
My OLD 220 Volt Sears air compressor (model # 106.15378) with twin

cylinders
recently quit being able to compress more than about 65 psi into the tank.
At that point, the motor still runs, the fan belt starts to squeal, and

the
cylinders will no longer run. I can't even "turn" the flywheel by hand.
Lowering pressure a lot lets it run again.
I'm assuming something (reed valve??) is causing the high pressure air to
"work" against the cylinders so hard that they will simply not pump. (I
wonder if storing the compressor in my hot Texas shop -- 140 degrees in

mid
PM -- contributed to this!)
Any ideas? "IF" it's a reed valve, is it accessible at the top of the
cylinder block? Is there a difference between the "input air" and output
air" reed valve? Can I fix a reed valve? ANY comments would help!!
Thanks.

EW





  #4   Report Post  
Old August 14th 03, 05:12 AM
DoN. Nichols
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

In article ,
EW wrote:

"jim" wrote in message ...
EW

you have two valves in almost all compressors:

SNIP............

Jim, may I ask another set of questions about the valves!

My compressor's twin cylinders flow compressed air out the large tube to an
"assembly" prior to the tank. This assembly has a vertical "safety valve"
and an electrical gizmo that tells the motor to shut off at a certain
pressure (mine is 125 psi, and has worked there until recently). Then the
assembly's output goes to the tank.


Hmm ... not like my old Sears compressor -- a 12 gallon
two-cylinder (but not two-stage), with a combination controller switch
and a regulator. The big line goes from the cylinder head directly into
the tank, and a separate line comes back out of the tank to the
regulator/switch. A smaller line goes from the cylinder head to the
regulator/switch, and that is what vents the cylinder to air when the
switch commands "stop". The safety overpressure valve is screwed into
one side of the regulator, and the output connection into the other
side, both facing out towards the operator.

OK. Is the "load valve" that you talked about at the cylinders' head
assembly, where I may get to it easily, or closer to the tank at the other
assembly? I assume the "check valve" is in that lower assembly somewhere,
and it will be a bear to take off.


I think that the check valve is in the head of mine (as one of
the two reed valves) and the load (or unloader) valve is in the
switch/regulator assembly.

IF the load valve, which I hope is the problem, is on the head above the
cylinders, then I will try that first. I should be able to see something
wrong, if that's the problem, right?


What I would suggest that you do (and what I did when I
discovered that the regulator fed out tank pressure no matter what the
setting) is go to the Sears web page, and spend some time chasing down
the service section which gives drawings for the various assemblies for
the different models. Those drawings told me enough about how my
regulator/switch was made to guide me in the disassembly, cleaning and
reassembly. It had some white corrosion in it from long-trapped water.
I scraped that clear, and added a touch of light oil to the moving
parts, and it now works just as it should.

Note that it was only the regulator which was misbehaving on
mine. The shutoff switch stopped the compressor at 100 PSI as it should.

So -- go to the http://www.sears.com page, download the images
and print the screen to save a copy.

You know -- one other possibility with this, since yours is a
220V one, and something which hit someone else in the newsgroup
recently. Someone had wired a new power cord onto the motor, and
somehow wired it so the 220V motor was actually getting only 110V. :-)

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---
  #5   Report Post  
Old August 14th 03, 01:16 PM
Loren Coe
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

In article , jim wrote:
EW wrote:

"jim" wrote in message ...
EW
you have two valves in almost all compressors:

SNIP............

Jim, may I ask another set of questions about the valves!

My compressor's twin cylinders flow compressed air out the large tube to an
"assembly" prior to the tank. This assembly has a vertical "safety valve"
and an electrical gizmo that tells the motor to shut off at a certain
pressure (mine is 125 psi, and has worked there until recently). Then the
assembly's output goes to the tank.

OK. Is the "load valve" that you talked about at the cylinders' head
assembly, where I may get to it easily, or closer to the tank at the other
assembly? I assume the "check valve" is in that lower assembly somewhere,
and it will be a bear to take off.


the unloader can be integral with the pressure sw assy or seperate,
it depends entirely on the design. in either case, it vents the
pipe that supplies air from the compressor head. this valve will
never be at the head or in the head casting.


IF the load valve, which I hope is the problem, is on the head above the
cylinders, then I will try that first. I should be able to see something
wrong, if that's the problem, right?

Thanks a million for your patience and knowledge. And, sorry!

EW

the unloader valve is about 1/4 inch wide, real small, with what looks
like a staight pin stiling out the bottom.. on my 1 hp. sears air com.


if you see this "pin", you have an integral unloader. it can be replaced,
cleaned or bypassed. a new one is included with a new pressure sw assy.
often it is easier (if cleaning doesn't help) to add an inline unloader.

lots of good advice in the thread, so you have no excuses now, let us
know when you get it fixed. good luck, --LOren
it is on the rt. side(OK, i know, thats not much info.. but when you
turn the crank on the side to turn the compressor off by hand this piece
of bendt metal hits a piece of metal and this hits the bottom of the
unloader valve... the unloader valve is screws right into the end of the
small 1/4 in. tubing that comes from the compressor to the tank area...
you probably have all the plastic covering still on the compressor???
it has to come off so you can see whats happening... and no the valve
that you described does not bother the large tubing that goes straight
to the compressor.. on mine the check valve screws right into the tank
just next to the assembly that you mentioned(and the unloader valve is
attached to the other side..

with your model number yuou can go on sears web site and enter the mod.
number and check for parts.. then you can get a diagram of the air
compressor....if the tubing breaks off, like it happened on mine. i just
went to ace hardware store and bought some copper and another brass
fitting and put it on.. the old alum. tubing might be brittle.....



  #6   Report Post  
Old August 14th 03, 06:55 PM
Gary R Coffman
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

On Wed, 13 Aug 2003 16:14:17 -0500, "EW" wrote:
My OLD 220 Volt Sears air compressor (model # 106.15378) with twin cylinders
recently quit being able to compress more than about 65 psi into the tank.
At that point, the motor still runs, the fan belt starts to squeal, and the
cylinders will no longer run. I can't even "turn" the flywheel by hand.
Lowering pressure a lot lets it run again.
I'm assuming something (reed valve??) is causing the high pressure air to
"work" against the cylinders so hard that they will simply not pump. (I
wonder if storing the compressor in my hot Texas shop -- 140 degrees in mid
PM -- contributed to this!)
Any ideas? "IF" it's a reed valve, is it accessible at the top of the
cylinder block? Is there a difference between the "input air" and output
air" reed valve? Can I fix a reed valve? ANY comments would help!!


Yeah, you probably have a broken output reed valve. That's letting one cylinder
pressurize the other when its piston is at the bottom of its travel. Effectively
the compressor is trying to be a two stage compressor, but the system isn't
designed for that. So when you hit 65 PSI, the second cylinder is actually
trying to pump 130 PSI, and it can't. The problem can't be the unloader
because the compressor starts and runs for a while before stalling. It can't
be a stuck check valve because some pressure builds in the tank.

The reed valves are mounted in a plate under the head. Generally there'll
be enough corrosion that you won't be able to remove and replace only one
reed valve. You'll have to replace the plate and valves as an assembly.

Gary


  #7   Report Post  
Old August 14th 03, 10:19 PM
EW
 
Posts: n/a
Default Old Sears Air Compressor - Help Please


"Loren Coe" wrote in message
news
Thanks Loren. As you say, I have all the info I need. If only I had more
mechanical skills....!!

Regards.

EW



  #8   Report Post  
Old August 14th 03, 10:29 PM
EW
 
Posts: n/a
Default Old Sears Air Compressor - Help Please


"Gary R Coffman" wrote in message
news

The reed valves are mounted in a plate under the head. Generally there'll
be enough corrosion that you won't be able to remove and replace only one
reed valve. You'll have to replace the plate and valves as an assembly.

Gary



Now, THIS I can handle. The parts you're writing about are very accessible.
The trick will be to see if my local compressor store here in Abilene, TX
can get the part(s) since this is an old compr. Your explanation of why
it's likely not a check or loader valve is very important.
Many Thanks.

EW



  #9   Report Post  
Old August 15th 03, 02:11 AM
lcoe
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

EW wrote:

"Gary R Coffman" wrote in message
news

The reed valves are mounted in a plate under the head. Generally there'll
be enough corrosion that you won't be able to remove and replace only one
reed valve. You'll have to replace the plate and valves as an assembly.
Gary

Now, THIS I can handle. The parts you're writing about are very accessible.
The trick will be to see if my local compressor store here in Abilene, TX
can get the part(s) since this is an old compr. Your explanation of why
it's likely not a check or loader valve is very important.
Many Thanks. EW


yes, if this is indeed the problem, Gary should get an award...., rcm'r of the
year? good luck! --Loren




  #10   Report Post  
Old August 15th 03, 09:16 AM
Gary Coffman
 
Posts: n/a
Default Old Sears Air Compressor - Help Please

On Fri, 15 Aug 2003 01:11:16 GMT, lcoe wrote:
yes, if this is indeed the problem, Gary should get an award...., rcm'r of the
year? good luck! --Loren


Actually, Don Young posted essentially the same answer, and according to
the time stamps, he beat me to it.

Gary



Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sears air compressor starting problem Jim Stuyck Metalworking 9 July 14th 03 01:03 PM


All times are GMT +1. The time now is 08:10 PM.

Powered by vBulletin® Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright 2004-2021 DIYbanter.
The comments are property of their posters.
 

About Us

"It's about DIY & home improvement"

 

Copyright © 2017