Brake Judder ....

skyestuart

Junior Member
Messages
42
My new to me 3200GT has a brake judder issue. Its not so bad that I cant use the car, but I'd like to fix it. The brake disks where all replaced in a previous service (about 3000 miles go) However the car really has hardly been used since then. I'm guessing its probably lack of use and maybe the pads are the issue. Looking for advice if this is a common issue? I should be able to rig up a dial gauge to check if the disks are true. So any help appreciated.
 

allandwf

Centenary Club
Messages
8,072
I would check a caliper piston hasn't seized through lack of use. That would also cause juddering.
 

davy83

Member
Messages
2,072
I have struggled with brake judder for a while now and still not got to the root of it entirely. I have had the calipers re-manufactured and this helped as a couple of the pistons were getting corroded and sticking. I like you replaced the discs twice, and have had one set skimmed and found they were well off not long after fitting, so they do buckle under heat. I had one of my wheel bearings gone and this contributed, now replaced. I recently had my wheels sent to a wheel refurbishment outfit and had two of them straightened as they were off round on the inside from pot holes I guess and this helped a lot.
I think its also worth checking bottom ball joints and suspension bushes especially at the front. I suspect also if your shocks are on the way out this might not help although I would expect vibration when driving and not just braking.
 

skyestuart

Junior Member
Messages
42
I drives fine, no issues with that. I think the shocks are ok the car has only done 30,000 miles. Stuck caliper piston is possible I've had that on previous cars .... I'll have a look next weekend or maybe get a local garage to do it as I'm getting lazy in my old age :)
 

davy83

Member
Messages
2,072
The front calipers are the most prone to sticking i think as there are 4 pots so more stuff to stick!!! any decent garage could advise on sticking pistons i guess.
 

conaero

Forum Owner
Messages
29,612
It will be the callipers I struggled with the same on my 32.

Also do some googling for Porsche callipers sticking, there are several write ups about Ali corrosion lifting the pad guides.
 

ChrisH

Junior Member
Messages
86
It will be the callipers I struggled with the same on my 32.

Also do some googling for Porsche callipers sticking, there are several write ups about Ali corrosion lifting the pad guides.
Porsche owners get very obsessed with totally re building the calipers... and whilst that is no doubt the 'correct' thing to do... if it is just a mild case sufficient cleaning... a subtle grind / file of the pad plate and a little very carefully applied copper grease... is in my opinion a much more pragmatic solution.

Removing the aluminium shims is a nightmare... the hex bolts will strip 9/10 so whilst it may sound simple... most instances will turn out to be much harder.

Applicable to all brembo brakes of the era as I'm aware... so most 4200s as well... maybe they got better?