Anyone help with brakes.. PLEASE!!!!

[Marco34]

Hi
Can anyone help please!!!!!!! before I go mad!

My problems still continue with brakes. Having replaced the front with discs and pads with just new pads on the rear, I have been experiencing higher temperatures on the offside front disc and caliper. EBC discs with Greenstuff pads.

I have stripped the brakes twice since, checked all surfaces are clean where the stub axle and disc meet, and bled the system. I gave up and took it to a brakes specialist. They found that the caliper was not releasing fully (the piston was not returning correctly). I tested this myself but didn't think the disc was overly grabbing. Anyway, they changed the caliper and tested the disc for runout. It is slightly out but within tolerance. The guy said that the slight temperature difference may well bed in. It's no different now than it was when I took the car in.

I've just given it a run and the offside caliper was almost too hot to touch and the near side was hot but bareable. The rear discs were very hot too, never have they been so hot, probably due to the new pads.

Will the better pads and discs cause more heat? Is the uneven heat on the front due to bedding in? I've done a steady 350 miles since fitting and am starting to brake harder now.

Any thought most appreciated? I've posed this on a few Audi sites as I'm hoping to find some answers...

Cheers

[Crasher]

Presumably this is an A4? Have you had any problems with water getting into the car from a blocked drip tray drain under the battery? If so, you probably have a faulty servo as when they sit in water, they pull in tiny amounts of water around the crimp seam and eventually start to rust inside, preventing the pedal from returning properly. The diesels seem to suffer more from this, presumably due to the higher vacuum developed continuously by the vacuum pump or it could just be that there are more diesel than petrol A4’s/Passats etc. The same symptom can also be had from a collapsed brake hose from someone using clamps on the hose during work.

[Sam]

Did they completely change the caliper or refurb your old one?

[Marco34]

Presumably this is an A4? Have you had any problems with water getting into the car from a blocked drip tray drain under the battery? If so, you probably have a faulty servo as when they sit in water, they pull in tiny amounts of water around the crimp seam and eventually start to rust inside, preventing the pedal from returning properly. The diesels seem to suffer more from this, presumably due to the higher vacuum developed continuously by the vacuum pump or it could just be that there are more diesel than petrol A4’s/Passats etc. The same symptom can also be had from a collapsed brake hose from someone using clamps on the hose during work.

Cheers for the fast response Crasher.. Yes it's an A4 1.9TDI. I have had the waterlogged problem and the brake sticking problem. That's all be sorted about 12 months... that caused sticking brakes!!!

All that is clear. The car has never had anyone working on the brakes other than me. I've also fitted a new brake pipe on the offending side just to make sure. Could it be the other disc isn't working as well and I'm thinking the hotter one is at fault? Mind you it's had MOT and all the checks from the brake specialist where I had it done...???

Cheers

[technohippy]

i have an a4 (b6) 1.9tdi and have noticed that the off-side front brake pad has far less wear on it than the near side one a few weeks back after calling audi for a new ashtray they told me of a re-call i needed which was something to do with the drip tray under the battery i believe, anyone got any thoughts on what i should be looking for or inspecting
the near-side brake always feels hotter when ive driven somewhere but im not sure if thats because its stuck on or if the other side isnt working as well.

[Crasher]

Your servo is full of water and rust.

[technohippy]

haha how very concise are they pricy to fix? and do you rekkon its the pad thats worn that has the buggered servo or the other side

[Crasher]

It is a pricey job as usually the master cylinder is also damaged; it costs about £600 (servo £250, M/C £130 and 2 hours labour plus a brake bleed) to do. The servo fills with water as the plenum chamber drains get blocked; there are a number of threads about this on the Passat/A4/A6 on this forum (https://www.vwaudiforum.co.uk/forum/s...ad.php?t=23548). For some reason the problem affects the left front first and then the right rear which is on the same circuit.

[technohippy]

how buggersome! sounds like its not a diy jobby either..... i was going to ask if i could get audi to sort it as its a fault stemming from a re-call issue but i dont think ill have much luck looking at the past threads, ahh well
hopefully it will pass its mot

[tyberwan]

For some reason the problem affects the left front first and then the right rear which is on the same circuit.

I guess you must have read my threads about this. Same problem..

https://www.vwaudiforum.co.uk/forum/s...ad.php?t=38015


Crasher, when you say it seems to affect the left front first, I assume you are talking about Left Hand drive cars. Would it be the same for Right Hand drive cars (mine is) where the servo would be located on the right side of the engine looking from inside the car?

My car had the left front heating up.