BruceWard

The clutch is in now so I was able to get the car off stands and take the front wheels off to try to finish up bleeding the brakes.

So far I have only tried the right front. I was able to bleed the inside bleed valve easily using the power bleeder. But the outside bleed valve still does nothing. I tried removing the valve and inserting the thin wire from the inside of a wire tie inside the caliper to try to dislodge any blocking. This did not produce any movement in the brake fluid.

I also read in the dealer service manual that a power bleeder should be used with 1.5 bar of pressure, thats 21.75 PSI. I have not been over 16 PSI so far, perhaps some extra pressure would help?

Any opinions on removing the bottom crossover pipe and bleeding out the bottom of the caliper from there?

Any other suggestions?

Anyone think I need to rebuild the calipers?

User 41221

My guess is that your caliper needs to be rebuilt. Out of curiosity, did it seem like you have an over abundance of brake dust on that particular wheel, more so than the others?

Regards,

BruceWard

I have not noticed additional brake dust on any of the wheels. I cannot bleed the outside valve on either of the front calipers.

I am beginning to thing rebuilding is a good idea. Does anyone know where I can get parts to rebuild or somewhere I can send them to be rebuilt?

RajDatta

Bruce, was there even wear even between inner and outer rotors? If so, you should be ok. You might not be building enough pressure to work the outside pistons.
Remove the rotors and check their seals to be sure. If seals look intact and you are not losing fluid, I wouldn't worry too much.
Raj

Phil Harrison

I have a hard time imagining the crossover pipe or bleed nipple are so blocked that no fluid comes out at 16 psi!

Can you open the bleed nipple & pump the brake peddle - fit a standard bleed pipe over the nipple fist & make sure you don't spray fluid everywhere...

BruceWard

I took the front drivers side (left) wheel off and beld the inside first then the outside. It bled fine. Then I tried the right one again and still no luck on the outside bleed valve. So 7 out of 8 bled fine and its just that last one.

I tried pumping the power bleeder up to 22 and still nothing came out.

We tried pumping the brakes previously and a the flow was limited. Never got it out more than two inches into the tube.

I noticed that I could see air between the outside pad and rotor but I could not turn the rotor. With the system pressurized to 22psi and not being able to turn the rotor I believe that the brake was clamped. I got a feeler guage out and was able to slide a .36 mm blade beween the outer pad and the rotor. But even the .11 blade would not fit between the inside pad and the rotor.

RajDatta

Sounds like your pistons are binding. I would remove the caliper for further inspections and try to push it in with my hands and see if that helps. Make sure not to pump the brake pedal while the caliper is out or the pistons will pop out.
It could just be some brake particles binding the pistons. Use lots of brake cleaner and maybe it will unbind itself. Post some pics if you can.
Thanks.

User 41221

Thats the same reason why I was asking about the brake dust. Usually when the bind, they get stuck half in/half out and cause the brake pad to grind itself into oblivion. Raj, are you thinking that the outside piston is stuck inside the caliper?

It still sounds like caliper rebuild time to me.

Regards,

BruceWard

Scott do you know where I can get parts for a caliper rebuild (non M030).

Does anyone know of stock, M030 or CS calipers for sale. Will M030 or CS calipers fit under stock 16" wheels?

RajDatta

Bruce, believe it or not, most parts are available thru the dealer. Look it up on the PET.
Scott, hard to tell without it being removed. Something is definitely wrong though.

BruceWard

I took the caliper off, only one of the four calipers moved when the peddle was pressed and there was a lot of chunks of some white plasticy material in there. Guess that explains a lot.

Ill post pics on Sunday.

The saga continues.....

BruceWard

Here are the pics so far

There was a lot of this stuff



in here underneath the pistons



The pistons very grimey and I chipped one removing it (from now on Ill used compressed air instead of prying with a screwdriver!)



I washed the pistons and they are oh so smooth



Unfortunately I did more damage removing them than I thought



Here is a shot of the end that does the work




The dust covers had holes in them. My plan going forward is to either find a place that will do it for me or order the parts and rebuild all four calipers. The front two certainly need it now and I doubt the rears are far behind.

Can anyone provide information on what I need to order and how to rebuild myself? Chuck @ Paragon said they can get the parts and I may be able to get additional advice from him.

Anyone know where I can send them to be rebuilt? I emailed Eric Sandoval tonight, perhaps he is in the business.

How do my badly removed pistons look. I had no question that I had damaged the one on the left and need to order a new one, but what about the others?

Once again thanks for all comments.

Moook

Bruce
Apparently M030 callipers will fit under 16" wheels OK.

Good luck in finding some though?

Hope the re-build goes OK.

Regards Dave.W

RajDatta

Bruce, if you have the PET cd, look up the part numbers. They are available thru Porsche and you should be able to order them through sunset Porsche.

BruceWard

Thanks Raj, the order is in with Sunset, I have new seals boots and pistons on the way for all four calipers.

Any suggestions on pads and rotors? My rotors are badly lipped and I think the one piston functioning thing must have done some bad stuff to the pads.

I have a lead on a full set of 88 S4 calipers with 40k miles on them , all four for $600 if anyone wants to upgrade to M030. Im going to stick with stock for now.