Binding rear caliper. Possibly.

KekseKaempfer

KekseKaempfer

A2OC Donor
Folks. Yet another todo has just been added to the list.

Seems that the drivers side rear caliper might be binding a touch. Seems to be only when reversing, the brake moans and whines, particularly after a run, when warm. There might be a faint whine, travelling forwards, it's difficult to tell.

So my question is: if I whip the caliper off and give it a good brushing down, and a clean, lube the pins, is that possibly going to help? Pads look reasonable, disks could maybe do with replacing. But i need to get the wheel off! to be sure. I hope I don't need a new caliper, and if I do, any experience of the Pagid one from ECP?

Cheers
Chris
 
KekseKaempfer said:
Folks. Yet another todo has just been added to the list.

Seems that the drivers side rear caliper might be binding a touch. Seems to be only when reversing, the brake moans and whines, particularly after a run, when warm. There might be a faint whine, travelling forwards, it's difficult to tell.

So my question is: if I whip the caliper off and give it a good brushing down, and a clean, lube the pins, is that possibly going to help? Pads look reasonable, disks could maybe do with replacing. But i need to get the wheel off! to be sure. I hope I don't need a new caliper, and if I do, any experience of the Pagid one from ECP?

Cheers
Chris
Click to expand...

First of all check that the handbrake cable is releasing properly.

Does the handbrake feel as if it is loose (ish) before the cables tighten and apply the brake. The first inch or so of handbrake operation should be more or less without resistance..

Also check at the callipers that the lever of the handbrake (on the calliper) is moving freely.

The handbrake is far more likely to be the cause than the calliper (not impossible though)

Steve B
 
Handbrake cables have an habit to deteriorate, I think they are top of the list of usual suspects.
If needed, aftermarket replacement calipers are not very expensive (approx 200GBP for the pair).
My A2 had the whole lot replaced this year.
 
Been out to check, in the dark. Springs already present on the caliper. Cable resets to stop point and appears to move freely. Perhaps a good clean will help. I'm also going to need new disks and pads. The binding one (outer, driver's side) is half the thickness of the others. Looks like it might have been rubbing for some time. And the rear shocks look terrible.

More work :(
 
Just to finish off.

Replaced the disks and pads today. Very easy job indeed. Just needed the caliper wind back tool and it was all done in an hour or so.

My 'binding' caliper appeared to be quite free, no sticking on the slider pins at all, very well lubed, I'd say. However, the piston itself was quite a bit harder to wind back in compared to the passenger side, So i'm going to keep an eye on it could be that the piston is seizing slightly.

here a a few pics of the new setup. The paint is just grey primer. I'm going to paint the calipers properly in the new year most likely. When I have a bit more time.

21845369403_3346805dc5_z.jpg

22278864248_3780166ee8_z.jpg

22466560045_4287534eec_z.jpg


interesting feature on the old disk. Looks like a fault in the disk to me.
22477528931_aa5a8e3b84_z.jpg
 
If the piston seems hard to compress try a brake rebuild using Biggred 'o' ring seals, new dust sleeves, etc. They can refurbish caliper too. If the car hasn't had a brake bleed (should renew every 2 years) moisture can effect the piston, or maybe dust sleeve is torn?
 
My handbrake has been acting a bit 'weird' lately. I had to take up an awful lot of slack at the lever end and then miraculously, the slack then re-appeared. So I figured, new cables were in order, probably due to stretching, or something.

Just been out to examine them (again) and although i can't see any obvious wear I find that the driver's side cable is not releasing properly, So this might have been the intermittent problem with my sticky caliper all along, even though i didn't see it when i did the brakes and disks.

Advice spot on as usual guys/gals. I'm going to replace the little springs at the same time, for beefier ones.

Chris
 
100% the same here, KekseKaempfer: handbrake always had slack but the driver side handbrake kept holding on; pads and slides were free and as I could manually release the handbrake mech on the caliper from the underside it became obvious that new handbrake cables were required: new cables fitted and issue sorted and a marked improvement in the improved the mpg: well it would, wouldn't it...
 
Hi all,

I have a sticking rear calliper on Audrey (TDI90), if I diagnose whether the handbrake system or calliper is at fault first, can a handbrake be lubricated if that is the issue, just like the calliper? Or must I replace the cables?

Is there a common cable wear or failure point to watch out for?

TIA.
 
dj_efk said:
Hi all,

I have a sticking rear calliper on Audrey (TDI90), if I diagnose whether the handbrake system or calliper is at fault first, can a handbrake be lubricated if that is the issue, just like the calliper? Or must I replace the cables?

Is there a common cable wear or failure point to watch out for?

TIA.
Click to expand...
Hi dj_efk,
My money would be on the guide tube being the culprit,
although it’s a 90 so will have disc brakes at rear pivot arm may be stiff , lubricate with spray & operate a number of times & see if it free’s off
Hope that helps
Keith
 
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