Sorry guys I am not really expecting an answer . It's just that I asked
in Uk.rec.cycling but it immediately degenerated into a trollfest.

I don't want to go the whole drill out the lever body, tap the hole
insert a helicoil reinsert bleed screw route. I think I would rather
just pay the £30 for a new lever set-up

Recently bled/burped my (Tektro)brakes but the wee screw that goes into
the lever feels like it has stripped. The front lever bleed screw
tightens fully but the bleed screw for the rear just spins .

Do I have no option but to buy a new lever for the rear brakes or does
someone have a way of rescuing the situation ?



C (or rather the wee hole it fits into).
https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

On 5 Apr 2021 at 06:49:08 BST, "soup" wrote:



Sorry guys I am not really expecting an answer . It's just that I asked
in Uk.rec.cycling but it immediately degenerated into a trollfest.

I don't want to go the whole drill out the lever body, tap the hole
insert a helicoil reinsert bleed screw route. I think I would rather
just pay the £30 for a new lever set-up

Recently bled/burped my (Tektro)brakes but the wee screw that goes into
the lever feels like it has stripped. The front lever bleed screw
tightens fully but the bleed screw for the rear just spins .

Do I have no option but to buy a new lever for the rear brakes or does
someone have a way of rescuing the situation ?



C (or rather the wee hole it fits into).
https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

The diagram lists a bolt for the bleeding port. Can you remove that, see
what's going on, and order the part that's failed?

I would err on the side of caution - a lot of pressure in those things.


--
Cheers, Rob

On Mon, 05 Apr 2021 06:23:41 +0000, RJH wrote:

I would err on the side of caution - a lot of pressure in those things.

Er, no, there is no pressure in there unless the lever is pulled. Even
then, it isnt much.

On 05/04/2021 07:31, Alan wrote:
On Mon, 05 Apr 2021 06:23:41 +0000, RJH wrote:

I would err on the side of caution - a lot of pressure in those things.

Er, no, there is no pressure in there unless the lever is pulled. Even
then, it isnt much.

Agreed it's atmospheric (or thereabouts) with lever relaxed but pressure
is massive when the lever is pulled. Force isn't that much, but as the
tubes are of such a small cross sectional area the pressure is WAY up
there .

Pressures at maximum braking are in the 1,500 PSI region
The tubing is designed to work up to the 2,000 PSI region.
Atmospheric pressure (depending on altitude and Temperature)
is in the 15 PSI region (think standard is 14.7)

soup wrote:
On 05/04/2021 07:31, Alan wrote:
On Mon, 05 Apr 2021 06:23:41 +0000, RJH wrote:

I would err on the side of caution - a lot of pressure in those things.

Er, no, there is no pressure in there unless the lever is pulled. Even
then, it isnt much.

Agreed it's atmospheric (or thereabouts) with lever relaxed but pressure
is massive when the lever is pulled. Force isn't that much, but as the
tubes are of such a small cross sectional area the pressure is WAY up
there .

Pressures at maximum braking are in the 1,500 PSI region
The tubing is designed to work up to the 2,000 PSI region.
Atmospheric pressure (depending on altitude and Temperature)
is in the 15 PSI region (think standard is 14.7)


Isn't there a reservoir of fluid in a bladder ?

I thought the bleed would be at atmospheric, the
reservoir provides fluid to the master, the master
provides mechanical advantage via the ratio of
master diameter to slave diameter (trades long throw
of brake lever to short throw of hydraulic calipers).

The bleed screw is not meant to be pressurized and is like
the plastic lid on the brake fluid reservoir in your car.

I've not been able to find a logical diagram of hydraulic
brake operation, nor even an exploded view of the parts
inside. Most of the articles seem to plagiarize one another,
as poor excuses for adverts.

*******

In this thread, they show a hydraulic brake level, where the
side plate (hides the reservoir bladder) has a pinhole.
No fluid should be on the inside of that pinhole, and the
pinhole is there so the bladder can move and not cause a vacuum
inside the covering with the two screws. If the bladder leaked
(and the bladder is at ambient, not pressurized), then that's
when the space the bladder lives in, would be wetted.

https://www.singletracks.com/forums/...re-a-pin-hole/

"overhaul the master cylinder...
debris blocking the feed port or return port"

And the reservoir is there to feed the feed port or
accept fluid from the return port.

One article says the Tektro family uses mineral oil
and does not gather water or corrode stuff. And it
should have printed near the lever, that it uses
mineral oil. Like a car, different brands use
different fluids, and the wrong fluid is "death to
seals".

It should have a few similarities to a bottle jack,
only a really tiny one.

The bleed screw then, needs to "lock", the plastic ring
on the screw needs to maintain integrity so fluid does not ooze
past. But it really shouldn't "blow" because the reservoir
is at ambient. Some "cover screws" (my bike has some
for other purposes), they only rotate a partial turn
and are a curse (flimsy). Rather than being stripped,
I'd inspect to see what type of screw it is. Fully threaded,
or just a 90 degree turn for "closure". A kind of "cap"
and not a screw.

Paul

On 05/04/2021 17:05, Paul wrote:
soup wrote:
On 05/04/2021 07:31, Alan wrote:
On Mon, 05 Apr 2021 06:23:41 +0000, RJH wrote:

I would err on the side of caution - a lot of pressure in those things.

Er, no, there is no pressure in there unless the lever is pulled. Even
then, it isnt much.

Agreed it's atmospheric (or thereabouts) with lever relaxed but pressure
is massive when the lever is pulled. Force isn't that much, but as the
tubes are of such a small cross sectional area the pressure is WAY up
there .

Pressures at maximum braking are in the 1,500 PSI region
Â*The tubing is designed to work up to the 2,000 PSI region.
Atmospheric pressure (depending on altitude and Temperature)
is in the 15Â* PSI region (think standard is 14.7)

Isn't there a reservoir of fluid in a bladder ?

I thought the bleed would be at atmospheric, the
reservoir provides fluid to the master, the master
provides mechanical advantage via the ratio of
master diameter to slave diameter (trades long throw
of brake lever to short throw of hydraulic calipers).

The bleed screw is not meant to be pressurized and is like
the plastic lid on the brake fluid reservoir in your car.

Hadn't thought of that the pressure in the tube will vary from
atmospheric up to 1500 PSI or so. But the pressure on the screw will
not vary so much
I've not been able to find a logical diagram of hydraulic
brake operation, nor even an exploded view of the parts
inside. Most of the articles seem to plagiarize one another,
as poor excuses for adverts.

Try page 5 of this :-
https://cdn.sram.com/sites/default/f...over view.pdf

Most are open systems but closed systems do exist but there are not a
lot of them



And the reservoir is there to feed the feed port or
accept fluid from the return port.

One article says the Tektro family uses mineral oil
and does not gather water or corrode stuff. And it
should have printed near the lever, that it uses
mineral oil. Like a car, different brands use
different fluids, and the wrong fluid is "death to
seals".

Yes I have mineral oil based fluid other stuff is called DOT something
or other

It should have a few similarities to a bottle jack,
only a really tiny one.

The bleed screw then, needs to "lock", the plastic ring
on the screw needs to maintain integrity so fluid does not ooze
past. But it really shouldn't "blow" because the reservoir
is at ambient. Some "cover screws" (my bike has some
for other purposes), they only rotate a partial turn
and are a curse (flimsy). Rather than being stripped,
I'd inspect to see what type of screw it is. Fully threaded,
or just a 90 degree turn for "closure". A kind of "cap"
and not a screw.

If it was the screw that was stripped I could probably just replace it
but it is the actual bleed port but as you say and thinking about it the
pressure in the reservoir doesn't vary much.
Just tried the brake again and it has held the fluid from yesterday
bleed screw/port interface feels only half stripped so maybe it has
enough friction (with the half thread and the wee rubber o-ring) to stop
fluid oozing out

On 5 Apr 2021 at 07:31:28 BST, "Alan" wrote:

On Mon, 05 Apr 2021 06:23:41 +0000, RJH wrote:

I would err on the side of caution - a lot of pressure in those things.

Er, no, there is no pressure in there unless the lever is pulled. Even
then, it isnt much.

Um, I did mean when the lever is pulled. It's obviously not much an issue in
any event when the brakes aren't being used ;-)

And while not deep sea pressures, I wouldn't trust, say, PTFE tape as
mentioned elsewhere. YMMV.

--
Cheers, Rob

On 05/04/2021 07:23, RJH wrote:
On 5 Apr 2021 at 06:49:08 BST, "soup" wrote:

Sorry guys I am not really expecting an answer . It's just that I asked
in Uk.rec.cycling but it immediately degenerated into a trollfest.

I don't want to go the whole drill out the lever body, tap the hole
insert a helicoil reinsert bleed screw route. I think I would rather
just pay the £30 for a new lever set-up

Recently bled/burped my (Tektro)brakes but the wee screw that goes into
the lever feels like it has stripped. The front lever bleed screw
tightens fully but the bleed screw for the rear just spins .

Do I have no option but to buy a new lever for the rear brakes or does
someone have a way of rescuing the situation ?

C (or rather the wee hole it fits into).
https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

The diagram lists a bolt for the bleeding port. Can you remove that, see
what's going on, and order the part that's failed?

It's the thread of that hole, so it's the main body,I don't think they
supply that separately, Even if they did, I think there would be
minimal cost difference between replacing that and buying a whole new
lever assembly

I would err on the side of caution - a lot of pressure in those things.

I am coming around to that way of thinking myself .
"Just buy a new lever assembly and have done".

Think I will try Chris's suggestion of PTFE tape first (have to make
sure there are no 'tags' on the tape as the tubes [carrying the
hydraulic oil] are very narrow and easily blocked leading to no brakes,
ARRGGGHHH!).

On 5 Apr 2021 at 07:39:15 BST, "soup" wrote:

On 05/04/2021 07:23, RJH wrote:
On 5 Apr 2021 at 06:49:08 BST, "soup" wrote:

Sorry guys I am not really expecting an answer . It's just that I asked
in Uk.rec.cycling but it immediately degenerated into a trollfest.

I don't want to go the whole drill out the lever body, tap the hole
insert a helicoil reinsert bleed screw route. I think I would rather
just pay the £30 for a new lever set-up

Recently bled/burped my (Tektro)brakes but the wee screw that goes into
the lever feels like it has stripped. The front lever bleed screw
tightens fully but the bleed screw for the rear just spins .

Do I have no option but to buy a new lever for the rear brakes or does
someone have a way of rescuing the situation ?

C (or rather the wee hole it fits into).
https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

The diagram lists a bolt for the bleeding port. Can you remove that, see
what's going on, and order the part that's failed?

It's the thread of that hole, so it's the main body,I don't think they
supply that separately, Even if they did, I think there would be
minimal cost difference between replacing that and buying a whole new
lever assembly

Ah OK - looks from that diagram that bolt 'C' screws into the lever, and a
non-shown screw is the bleed nipple. But I take it that the bolt is all there
is?


I would err on the side of caution - a lot of pressure in those things.

I am coming around to that way of thinking myself .
"Just buy a new lever assembly and have done".

Think I will try Chris's suggestion of PTFE tape first (have to make
sure there are no 'tags' on the tape as the tubes [carrying the
hydraulic oil] are very narrow and easily blocked leading to no brakes,
ARRGGGHHH!).

Indeed, might be worth a whirl as proof of concept, but there will be a lot of
pressure under hard braking.


--
Cheers, Rob

soup Wrote in message:r
Sorry guys I am not really expecting an answer . It's just that I asked in Uk.rec.cycling but it immediately degenerated into a trollfest.I don't want to go the whole drill out the lever body, tap the hole insert a helicoil reinsert bleed screw route. I think I would rather just pay the £30 for a new lever set-upRecently bled/burped my (Tektro)brakes but the wee screw that goes intothe lever feels like it has stripped. The front lever bleed screwtightens fully but the bleed screw for the rear just spins . Do I have no option but to buy a new lever for the rear brakes or doessomeone have a way of rescuing the situation ?C (or rather the wee hole it fits into).https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

Agree URC is trollfest, sad bunch. You might try
uk.rec.cycling.moderated but not much activity there
recently.
--
Biggles


----Android NewsGroup Reader----
https://piaohong.s3-us-west-2.amazon...net/index.html

On 05/04/2021 09:43, Biggles wrote:
soup Wrote in message:r
Sorry guys I am not really expecting an answer . It's just that I asked in Uk.rec.cycling but it immediately degenerated into a trollfest.I don't want to go the whole drill out the lever body, tap the hole insert a helicoil reinsert bleed screw route. I think I would rather just pay the £30 for a new lever set-upRecently bled/burped my (Tektro)brakes but the wee screw that goes intothe lever feels like it has stripped. The front lever bleed screwtightens fully but the bleed screw for the rear just spins . Do I have no option but to buy a new lever for the rear brakes or doessomeone have a way of rescuing the situation ?C (or rather the wee hole it fits into).https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

Agree URC is trollfest, sad bunch. You might try
uk.rec.cycling.moderated but not much activity there
recently.

Indeed last post there was 14th February.
Moderators still active?

On 5 Apr 2021 at 10:26:14 BST, "soup" wrote:

On 05/04/2021 09:43, Biggles wrote:
soup Wrote in message:r
Sorry guys I am not really expecting an answer . It's just that I asked in
Uk.rec.cycling but it immediately degenerated into a trollfest.I don't want
to go the whole drill out the lever body, tap the hole insert a helicoil
reinsert bleed screw route. I think I would rather just pay the £30 for a
new lever set-upRecently bled/burped my (Tektro)brakes but the wee screw
that goes intothe lever feels like it has stripped. The front lever bleed
screwtightens fully but the bleed screw for the rear just spins . Do I
have no option but to buy a new lever for the rear brakes or doessomeone
have a way of rescuing the situation ?C (or rather the wee hole it fits
into).https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

Agree URC is trollfest, sad bunch. You might try
uk.rec.cycling.moderated but not much activity there
recently.

Indeed last post there was 14th February.
Moderators still active?

Why not try posting there, it would give them something to talk about, and
there is a lot of expertise among the small coterie of contributors?

--
Roger Hayter

On 05/04/2021 10:44, Roger Hayter wrote:
On 5 Apr 2021 at 10:26:14 BST, "soup" wrote:

On 05/04/2021 09:43, Biggles wrote:
soup Wrote in message:r
Sorry guys I am not really expecting an answer . It's just that I asked in
Uk.rec.cycling but it immediately degenerated into a trollfest.I don't want
to go the whole drill out the lever body, tap the hole insert a helicoil
reinsert bleed screw route. I think I would rather just pay the £30 for a
new lever set-upRecently bled/burped my (Tektro)brakes but the wee screw
that goes intothe lever feels like it has stripped. The front lever bleed
screwtightens fully but the bleed screw for the rear just spins . Do I
have no option but to buy a new lever for the rear brakes or doessomeone
have a way of rescuing the situation ?C (or rather the wee hole it fits
into).https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

Agree URC is trollfest, sad bunch. You might try
uk.rec.cycling.moderated but not much activity there
recently.

Indeed last post there was 14th February.
Moderators still active?

Why not try posting there, it would give them something to talk about, and
there is a lot of expertise among the small coterie of contributors?

I did, on Saturday it still hasn't appeared.
As it takes someone's 'private time' to read and 'moderate' each post
.. I did not feel it was worth complaining

On 5 Apr 2021 at 10:44:21 BST, "Roger Hayter" wrote:

On 5 Apr 2021 at 10:26:14 BST, "soup" wrote:

On 05/04/2021 09:43, Biggles wrote:
soup Wrote in message:r
Sorry guys I am not really expecting an answer . It's just that I asked in
Uk.rec.cycling but it immediately degenerated into a trollfest.I don't want
to go the whole drill out the lever body, tap the hole insert a helicoil
reinsert bleed screw route. I think I would rather just pay the £30 for a
new lever set-upRecently bled/burped my (Tektro)brakes but the wee screw
that goes intothe lever feels like it has stripped. The front lever bleed
screwtightens fully but the bleed screw for the rear just spins . Do I
have no option but to buy a new lever for the rear brakes or doessomeone
have a way of rescuing the situation ?C (or rather the wee hole it fits
into).https://i.postimg.cc/9QxKZXrq/Screenshot-134.png

Agree URC is trollfest, sad bunch. You might try
uk.rec.cycling.moderated but not much activity there
recently.

Indeed last post there was 14th February.
Moderators still active?

Why not try posting there, it would give them something to talk about, and
there is a lot of expertise among the small coterie of contributors?

Agreed - I've had some good advice in the past.
--
Cheers, Rob

On Mon, 05 Apr 2021 06:49:08 +0100, soup wrote:

Sorry guys I am not really expecting an answer . It's just that I asked
in Uk.rec.cycling but it immediately degenerated into a trollfest.

I don't want to go the whole drill out the lever body, tap the hole
insert a helicoil reinsert bleed screw route. I think I would rather
just pay the £30 for a new lever set-up

Recently bled/burped my (Tektro)brakes but the wee screw that goes into
the lever feels like it has stripped. The front lever bleed screw
tightens fully but the bleed screw for the rear just spins .

Do I have no option but to buy a new lever for the rear brakes or does
someone have a way of rescuing the situation ?



C (or rather the wee hole it fits into).
https://i.postimg.cc/9QxKZXrq/Screenshot-134.png


https://forum.cyclinguk.org/viewforum.php?f=5
might be more helpful.

Cheers


Dave R


--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

On 05/04/2021 07:17, Chris Hogg wrote:
On Mon, 5 Apr 2021 06:49:08 +0100, soup wrote:



Sorry guys I am not really expecting an answer . It's just that I asked
in Uk.rec.cycling but it immediately degenerated into a trollfest.

I don't want to go the whole drill out the lever body, tap the hole
insert a helicoil reinsert bleed screw route. I think I would rather
just pay the £30 for a new lever set-up

Recently bled/burped my (Tektro)brakes but the wee screw that goes into
the lever feels like it has stripped. The front lever bleed screw
tightens fully but the bleed screw for the rear just spins .

Do I have no option but to buy a new lever for the rear brakes or does
someone have a way of rescuing the situation ?



C (or rather the wee hole it fits into).
https://i.postimg.cc/9QxKZXrq/Screenshot-134.png


PTFE tape on the bleed screw thread?

I'd have thought that a Loctite type thread locking compound might have
more chance as a quick and dirty fix. Add a jubilee clip around the lot
to clamp the screw in place? As tight as possible.