C3 Brakes seizing -help! - Page 2

Ringmaster · 26-05-18, 09:55 PM

Quote:

Originally Posted by John.

On my CQ the underbonnet temp gets pretty high I think.....and this is when my brakes would bind.
Does yours have a vacuum servo, if yes it would be easy enough to pull of the vacuum pipe when they're binding and see if they release ?.......if yes then servo not good. If you have vacuum servo!

It's boosted by the PAS pump.

Ringmaster · 26-05-18, 09:58 PM

Thanks chaps.......

John. · 27-05-18, 05:12 AM

Quote:

Originally Posted by Ringmaster

It's boosted by the PAS pump.

That's twice I've asked.

M4rkp · 27-05-18, 09:18 AM

It is certainly the master cylinder - its well documented on other forums (quattroforum.com for one!)
concensus of opinion says that its a heat soak issue having a detrimental effect on what could be (in your case certainly) very old rubber seals.......

Depending on the age of the MC that is on your car, the only way to get into the unit is to partially destroy it......however, for the cost of replacement its not really worth the hassle.

My 1986 car is now on its 5th replacement master cylinder - everytime displayed the same symptoms...binding brakes.

Ringmaster · 27-05-18, 11:25 AM

The M/C is original, so at 31 years I shouldn't be surprised if it's breaking down on the inside. Bit like me really!

The M/C is accessible to work on, so thankfully no major headaches there.

Thanks for your input chaps.....

Ringmaster · 13-06-18, 01:16 PM

Folks,

Looks like it was the front calipers, especially the front near side. The problem remained intermittent.

Calipers stripped down, cleaned, greased etc., and all seems ok now, but will keep fingers crossed in the short term.

I purchased a new MC anyway as I'm sure a suitable one would get harder to source in the future.

If, like me, you prefer to buy these things from a human being rather than on-line, for those of you in East Sussex I recommend Autolec Motor Factors. They have been able to supply a hard to get part for the C3 before and prices seem fair.

Duffy3074 · 13-06-18, 01:46 PM

How does that explain the rears getting hot as well?

Ringmaster · 13-06-18, 07:45 PM

It doesn't.....

But during the last couple of 'episodes' the rears were no hotter than one would expect.

Anyway, I'm not going to consider myself out of the woods until a few incident free weeks have elapsed....... So far so good today.

Duffy3074 · 13-06-18, 08:05 PM

Fair enough and hopefully that’ll be that

26-05-18, 09:58 PM	#12
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Thanks chaps.......

27-05-18, 09:18 AM	#14
M4rkp Grown up member Classic Audi Club Member Join Date: Feb 2013 Location: Sometimes Roberttown - sometimes Surrey Posts: 194	It is certainly the master cylinder - its well documented on other forums (quattroforum.com for one!) concensus of opinion says that its a heat soak issue having a detrimental effect on what could be (in your case certainly) very old rubber seals....... Depending on the age of the MC that is on your car, the only way to get into the unit is to partially destroy it......however, for the cost of replacement its not really worth the hassle. My 1986 car is now on its 5th replacement master cylinder - everytime displayed the same symptoms...binding brakes.

27-05-18, 11:25 AM	#15
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	The M/C is original, so at 31 years I shouldn't be surprised if it's breaking down on the inside. Bit like me really! The M/C is accessible to work on, so thankfully no major headaches there. Thanks for your input chaps.....

13-06-18, 01:16 PM	#16
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	Folks, Looks like it was the front calipers, especially the front near side. The problem remained intermittent. Calipers stripped down, cleaned, greased etc., and all seems ok now, but will keep fingers crossed in the short term. I purchased a new MC anyway as I'm sure a suitable one would get harder to source in the future. If, like me, you prefer to buy these things from a human being rather than on-line, for those of you in East Sussex I recommend Autolec Motor Factors. They have been able to supply a hard to get part for the C3 before and prices seem fair.

13-06-18, 01:46 PM	#17
Duffy3074 4 ring whore! Classic Audi Club Member Join Date: Aug 2015 Location: Dalgety Bay, Fife Posts: 2,078	How does that explain the rears getting hot as well?

13-06-18, 07:45 PM	#18
Ringmaster Senior Member Classic Audi Club Member Join Date: Apr 2008 Posts: 1,326	It doesn't..... But during the last couple of 'episodes' the rears were no hotter than one would expect. Anyway, I'm not going to consider myself out of the woods until a few incident free weeks have elapsed....... So far so good today.

13-06-18, 08:05 PM	#19
Duffy3074 4 ring whore! Classic Audi Club Member Join Date: Aug 2015 Location: Dalgety Bay, Fife Posts: 2,078	Fair enough and hopefully that’ll be that