Slate_Grey

I have an 89 3.2 Carrera. I just bought the car not too long ago -- had a PPI done by a Porsche dealer (San Diego). Unfortunately, I didn't get to talk to the tech, etc, but the car had "sticky caliper on right front" listed as the most severe issue.

I jacked the car up, rotated the wheel, and sure enough, something's dragging. Around town, once warmed up, brake squeal is heard while driving -- hit the pedal (while still moving obviously), squeal stops, release pedal, squeals again. This would indicate to me that indeed, the pad is not releasing from the rotor, n'est pas?

What I'd like to know is how to troubleshoot this before buying a caliper, installing, bleeding brakes, etc, etc. I figure, jack the car up, spin wheel. Notice drag. Remove wheel, remove pads, put wheel on, spin and see what happens? That just doesn't seem like a rock solid plan to me...Anyone got any ideas/experience? Are there other explanations that I should entertain before replacing the caliper?

Driver8

If you pull the pads, you should notice uneven wear between the pads. I would rebuild the caliper before replacing. It is cheap and easy, search the board for instructions.

A

KC911

I'm sure some brake experts will chime in, but if your rubber brake lines are original, imo they should be replaced, and could be a likely culprit to what you're experiencing. I had the same thing, and although I replaced the original rubber lines, that didn't fix my problem, and I ended up going with 930 calipers & rotors. Hope this helps...Keith

'88 Carrera

Crimson Nape Racing

caliper rebuilds are cheap & easy. I had the same problem with my 84 and got the parts from a local auto parts store for next to nothing. IIRC, it only consisted of a couple rubber parts. also, it would be a good time to paint the callipers while they're off the car.

Slate_Grey

Ok, well, I guess you guys are talking me into a rebuild. I have checked out the Pelican Parts site (tech article) and the only reason this scares me, is that I have to be at the track in a week and a half. Buying a loaded caliper is $200, but all I have to do is bleed... On the other hand, the rebuild is a decimal point less expensive I did just buy an air compressor, and this sounds like a good time to put it to good use

I was actually thinking about getting a rebuild kit, and a new caliper. That way I have a safety net if something goes wrong on the rebuild? Am I just being a wuss? The "20 degree" is making me nervous...

Anyone happen to know if the pressure bleeder with the ATE fitting (BMW and VW) will fit the Porsche mc resevoir?

kepster

I had a similar problem with my '74. I took out the pads, pumped the pedal to bring the caliper pistons out some, disconnected the brake fluid line from the caliper and (being careful not to damage anything) forced (pried) the caliper piston back in rapidly. This shot a bunch of milky white goo out of the caliper. I did it several more times and got more white goo. I kept pumping the brake (while monitoring my brake fluid level in the reservoir) and forcing the rotor back in. After a while I could do it with my hands since I had the fluid line off. I did it until there was no more white goo. It solved my problem.

fixnprsh

your brake line is probably starting to swell shut causing a slow bleed back of pressure, it happens, a caliper rebuild is also a very good idea and its fairly easy DIY and parts aren't too bad. do BOTH sides at the same time and lines, I reccomend flushing your brake fluid every two years, OR once a year if you live in a damp climate (and flush your clutch line and slave too if you have a G50 as this is often forgoten)

pjc

I think the guys have said it all - start with a refurb kit (while you are at it you may as well change the rubber hose). Personally I would not do just one side but both - same as replacement, I would not just replace one caliper (personal opinion guys!). Further, if the fronts are not good the backs can't be great either so plan to do all four corners then you know its right.

Not sure about the '89 car but on the assumption its not too different from the earlier models make sure the piston is replaced in the correct position - for the earlier cars there is a template required that can be made up from paper - its shown in the Haynes manual.

Have a great track day but do the brakes first!

PJC

rbcsaver

Any one have an opinion about using the "marketed" stainless steel pistons vs oem.
regards,
Steve

Peter Zimmermann

Forget your track day and fix your brakes! STEP 1. Reseal your sticky caliper using a reseal kit from Porsche. You will need assembly paste, part #000 043 117 00 (also from Porsche) - this paste will ease assembly and help break in the new seals more quickly. Replace all four rubber flex hoses - use only o.e. parts from Porsche or a high-quality independent. Bleed the entire system, I prefer Castrol LMA (which will also serve you well on track days in the future). STEP 2. Drive the car about 150 miles, reseal the other front caliper. STEP 3. Repeat step 2, reseal one rear caliper. STEP 4. Ditto, the last caliper. Note: Don't worry about the 20 degree deal - with a caliper held securely in a vise you can look at the pistons. Do one piston at a time, start to finish. As you re-insert it simply line it up with the untouched piston (they mirror image each other). Good luck!

g-50cab

You can get a rebuilt caliper from Vertex auto for under $100. But rebuilding is very easy - just don't stick your findgers in the middle of the caliper when the picton pops out!

rbcsaver

Ditto on do NOT place your fingers anywhere near the caliper insides when those pistons pop out!!
The most difficult part about the rebuilds is putting the metal banded outter rubber boot on. I have written a thread on this previously. Attached is a pic of the pvc piece about (about 5/8" high) that I made and it makes the install much easier. As I recall, I cut it from an elbow or similar piece (not expensive) and then I had to sand away some of the outtter thickness to fit.
Secondly, I disagree about the 20 degrees on the piston. Not hard to do and easiy to make a template. All you need is a 50 cent plastic protractor and some heavy paper board to get started. Also see pics.
regards,
Steve

mschafer71

Sometimes the brake pads upper and lower contact surfaces with the caliper are corroded or crapped out from pad dust, dirt, etc. I would first take out the pads and clean the contact surfaces that the pad slides in the caliper on when pushed for by the piston. You may have much more wrong than this, but my dragging pads were solved by a good cleaning of those contact surfaces and a touch of high temp grease.

rbcsaver

By high temp grease, I believe he means silicon grease. Just do not get it anywhere near the rotors or pads!!! You will not stop and it won't come off. Also, to rebuild do NOT separate the caliper halves. There is no need, unless the center seal is leaking.
regards,
Steve

pjc

Personally, I remove the pads and 'flush' the calipers with brake cleaning fluid annually - the grease talked about (I assume?) should be placed on the rear of the brake pad (on the metal face) that sits against the caliper piston - only reason really for this is to stop brake squeal. Using grease gives another good reason for flushing out the caliper annually - the grease gathers dust and can finish up as a clogging mess.

PJC