Jump to content

Recommended Posts

25 minutes ago, signalredshaker said:

Actually, it did! ..and there was.

I don't really think the elimination of these two wrongs are the only improvements one can make to a TR.

James

Adjustable rods are for cables not hydraulics

Link to post
Share on other sites
12 hours ago, signalredshaker said:

Actually, it did! ..and there was.

I don't really think the elimination of these two wrongs are the only improvements one can make to a TR.

James

 

11 hours ago, ntc said:

Adjustable rods are for cables not hydraulics

Standard on TR3, at least mine was fitted with them, however my pedal still goes down too far.

Ralph

Link to post
Share on other sites

I have just been looking on ebay and there are plenty of residual pressure valves on there, but seem to be 2 pressures available, 2psi and 10 psi. Unfortunately all in line types with metric fittings. 

Which poundage would be nearest to original fitment?  My car had a valve but it was all rusted up inside so deleted it on the re build.

Ralph

Link to post
Share on other sites

I've ran with and without the residual pressure valve inards, and it mad no difference.

I'm working through the suggestions here, and have eliminated the pedal hold down overnight, and rear brake adjustment. Done both and no difference, if I'm honest I didn't think there would be, 

I can't see my stub axles could flex, not with the big HD ones, and when I think of the force needed to retract pads when changing them, it takes some believing that the rubber dust covers can pull them back. I'm thinking about running without the covers, for a very short period of time to see, what does anyone think?

John.

Link to post
Share on other sites

On new callipers from Moss I could not get a firm peddle until I tried the ply pads at half or less thickness and jammed on over night. It worked for me. (not my TR)

My TR5 has all the uprated stuff including the CDD front stub axle/hub and bigger bearings.Someone has cured this problem by careful shimming of the bearing and stub axle set up and I am going to let him do mine to see if it will cure it which he is confident it will. Watch this space.

Regards Harry

Link to post
Share on other sites
2 hours ago, John Morrison said:

I've ran with and without the residual pressure valve inards, and it mad no difference.

I'm working through the suggestions here, and have eliminated the pedal hold down overnight, and rear brake adjustment. Done both and no difference, if I'm honest I didn't think there would be, 

I can't see my stub axles could flex, not with the big HD ones, and when I think of the force needed to retract pads when changing them, it takes some believing that the rubber dust covers can pull them back. I'm thinking about running without the covers, for a very short period of time to see, what does anyone think?

John.

John 

I would remove pads and shoes to check even ware

Edited by ntc
Link to post
Share on other sites

I had to change my pads before it’s MOT, when I took the old ones out they had about 1/8 of pad left on all 4 so good even wear on the pads, the pistons moved in and out as they should and the stainless steel was very clean and smooth, fitted new pads and checked that they operated correctly. Still get the same one push on the peddle and it goes to half way down second push and it’s about 1/4 down. 
 

Mike redrose group 

Link to post
Share on other sites
6 hours ago, BRENDA1 said:

I had to change my pads before it’s MOT, when I took the old ones out they had about 1/8 of pad left on all 4 so good even wear on the pads, the pistons moved in and out as they should and the stainless steel was very clean and smooth, fitted new pads and checked that they operated correctly. Still get the same one push on the peddle and it goes to half way down second push and it’s about 1/4 down. 
 

Mike redrose group 

Suggest you read my post above again 

Link to post
Share on other sites
On 8/2/2021 at 8:00 AM, John Morrison said:

I've ran with and without the residual pressure valve inards, and it mad no difference.

I'm working through the suggestions here, and have eliminated the pedal hold down overnight, and rear brake adjustment. Done both and no difference, if I'm honest I didn't think there would be, 

I can't see my stub axles could flex, not with the big HD ones, and when I think of the force needed to retract pads when changing them, it takes some believing that the rubber dust covers can pull them back. I'm thinking about running without the covers, for a very short period of time to see, what does anyone think?

John.

John,  I don`t think it is the dust covers but the main seals that relax after being under pressure, indeed they are designed to do so to allow the pads to move back very slightly. I think the main cause is play in the front wheel bearings. I was always taught that there should be some otherwise the bearings are too tight, but needs to be barely detectable.

A simple check might be to "pump up" the brake pedal with the car stationary, then without moving the car leave for a short while and then press the brake pedal again. If the pedal has stayed up, then the culprit is probably pad knock back when moving ( warped disc or loose wheel bearings), if the pedal goes down to the lower position try it again with the handbrake applied to eliminate back brake adjustment.

This was obviously a problem from the start, otherwise why would Triumph have gone to the trouble of installing the residual pressure valve. I am tempted to install one of the new commercially available items, starting with the 2psi version, but I don`t want to disturb the brake hydraulics at the moment, prefer to be out driving the car whilst the weather permits.

Ralph.

Edited by Ralph Whitaker
Link to post
Share on other sites

Yes, they are designed to do so and with the wear out of the brake pads the pistions slide more and more out through the seals - but in steps and not constantly exactly according to the wear out.

So the problem of the play can be less after driving some or less miles, until the pistons move out in a step, and can also increase again....

 

Edited by Z320
Link to post
Share on other sites

Thanks all.

 

still working through these, and other suggestions.

Neil, can't see that my brakes need bled, I've done the job so many times, sometimes with others, power bled too, plus the pedal is hard, not at all spongy.

I'll keep all posted, as it seems a problem for more than just me.

John.

Link to post
Share on other sites
  • 2 weeks later...

FIXED!

Yes fixed and I'm so chuffed!

Many thanks to all the folk here, as well as those who read of my issue elsewhere and got in touch directly.

The issue came down to two things, front whel bearing play, and the rear backplates.

Front wheel bearing play, in some ways obvious, we run with slight, just discernable rock on the fronts - Yes? Well I'm convinced now that any rock is what causes the pads to move, not flexing stub axles or rubber covers or seals, and causes pad knock back. So making sure that the play in front bearings is, JUST, discenable is part of the answer.

Second issue is wear in the rear backplate, caused by the handbrake lever, I know that Stuart for one, mentions this often, but I never put this and my pedal travel together, well I should have.

Before and after photos of a very simple fix, build up the groove, or indent, with weld and grind flush, refit, making sure cylinders slide, if you don't grind back enough, then the cylinder will bind when all clipped back togetehr - ask me how I know, and it only takes a few thou!

Test run, and the jobs a Gud'un.

John.

360189569_forumsixebackplate.jpg.5aaa72b49cb740b103e7ba6e3f5ed9f9.jpg

 

 

1278353720_forumbackplateresized2.jpg.eae2769eef4c84b1d1f97ddf2b13f551.jpg

Link to post
Share on other sites
On 8/12/2021 at 11:48 AM, John Morrison said:

FIXED!

Yes fixed and I'm so chuffed!

Many thanks to all the folk here, as well as those who read of my issue elsewhere and got in touch directly.

The issue came down to two things, front whel bearing play, and the rear backplates.

Front wheel bearing play, in some ways obvious, we run with slight, just discernable rock on the fronts - Yes? Well I'm convinced now that any rock is what causes the pads to move, not flexing stub axles or rubber covers or seals, and causes pad knock back. So making sure that the play in front bearings is, JUST, discenable is part of the answer.

Second issue is wear in the rear backplate, caused by the handbrake lever, I know that Stuart for one, mentions this often, but I never put this and my pedal travel together, well I should have.

Before and after photos of a very simple fix, build up the groove, or indent, with weld and grind flush, refit, making sure cylinders slide, if you don't grind back enough, then the cylinder will bind when all clipped back togetehr - ask me how I know, and it only takes a few thou!

Test run, and the jobs a Gud'un.

John.

360189569_forumsixebackplate.jpg.5aaa72b49cb740b103e7ba6e3f5ed9f9.jpg

 

 

1278353720_forumbackplateresized2.jpg.eae2769eef4c84b1d1f97ddf2b13f551.jpg

 

Link to post
Share on other sites

Thank you for the before and after photos, it now makes a lot more sense. I thought I was looking for wear in the rectangular hole itself and found none when I stripped the brakes recently. Luckily I took photos whilst the lever and slave cal were off the backplate and now I can see what to look for. I have the start of some wear, but nothing like yours,so I'll know to keep an eye on it.

Link to post
Share on other sites

2D47BC7C-5F48-4481-9818-7EA51FEDD4C1.thumb.jpeg.9dd72ac3fc4b07d2486424c26b32efdc.jpegI had the same problem on my TR4A during lockdown. With no access to welding, I fettled a U shaped shim from a standard timber saw blade and slipped it in between the piston holder and the backing plate to allow the piston to slide unimpeded.  The saw blade shim is only about 1 mm thick so easily slipped in with some copper grease - it works a treat.  I also fashioned an extended pivot arm using angle iron as per Roger’s diagram to achieve a very satisfactory handbrake function.

David

Edited by Pontious
No name
Link to post
Share on other sites
On 8/12/2021 at 11:48 AM, John Morrison said:

FIXED!

Yes fixed and I'm so chuffed!

Many thanks to all the folk here, as well as those who read of my issue elsewhere and got in touch directly.

The issue came down to two things, front whel bearing play, and the rear backplates.

Front wheel bearing play, in some ways obvious, we run with slight, just discernable rock on the fronts - Yes? Well I'm convinced now that any rock is what causes the pads to move, not flexing stub axles or rubber covers or seals, and causes pad knock back. So making sure that the play in front bearings is, JUST, discenable is part of the answer.

Second issue is wear in the rear backplate, caused by the handbrake lever, I know that Stuart for one, mentions this often, but I never put this and my pedal travel together, well I should have.

Before and after photos of a very simple fix, build up the groove, or indent, with weld and grind flush, refit, making sure cylinders slide, if you don't grind back enough, then the cylinder will bind when all clipped back togetehr - ask me how I know, and it only takes a few thou!

Test run, and the jobs a Gud'un.

John.

360189569_forumsixebackplate.jpg.5aaa72b49cb740b103e7ba6e3f5ed9f9.jpg

 

 

1278353720_forumbackplateresized2.jpg.eae2769eef4c84b1d1f97ddf2b13f551.jpg

Are the two round pivots that caused that wear in the back-plate sill round or worn flat one side?

Edited by BlueTR3A-5EKT
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.