father2nate

Well, I should have just waited for the wrencing GTG to do this, but damnit, I always get in a hurry to fix her....

I pulled all 4 calipers and installed the rebuild kit. It was a b!tch getting a couple of the pistons in, but they finally went.

I reinstalled the calipers, and bled the system. Put super blue in there. (Pissed because the master cylinder is leaking where it connects to the booster. Going to worry about that later.

Well, got the wheels back on, new coolant in, and took off. The brakes are spongy as hell now. Less responsive than before.

And, when heading home, started to pull hard left... looks like the driver's side caliper is stuck.... again....

WTF?

Why are the brakes spongy now? (I installed new brake hoses, too)



Oh, and looks like I need a wheel bearing on the passenger rear wheel. Does it end? no.

Campeck

my car did the same thing. rebuild...spongyness.
didn't ever figure out why. its a little better now. but its been a while.

hoffman912

did you bleed it at the master? it coudl still have air in the master.. bleed it there, then do all 4 corners again, make sure you get all the air out.

father2nate

What is the procedure for bleeding at the master? Can you point me somewhere, or let me know. Thanks!

Manning

Master cylinder leaks? Better fix that now before you put your head up somebody else's ***. I almost stuffed my Scirocco up somebodies backside because of a leaky master.

I think Harry is talking about bench bleeding, which I don't think you need to do since you didn't replace the master. On the other hand, freshly rebuilt calipers can have trapped air no matter how well you think you bled them. Drive around a bit to shake the bubbles loose, then tap on the calipers with a hammer before you re-bleed them. I am NOT making this up.

luckett

You have air somehwhere in the system. Are you sure your master cylinder fuid level did not get too low while bleeding?

I don't know the early calipers. Do they have pistons on both sides? My 968 calipers need to have both sides of the caliper bled.

Did you inspect and measure the clearance on the bores/pistons and refinish the caliper bores before installing the seals?

Manning

Single piston sliding calipers.

luckett

What do you mean "looks like"? Are you sure it's sticking?

father2nate

When I finished removing the calipers, the master cylinder was empty. Air could have got in it then.

I did not measure the bores/pistons, but I clean them up with some fine sandpaper.

"Looks like" - I was making a guess. I will jack up the front and spin the wheel to see if it is sticking.

Dmitry S.

To bleed the air out of the master, have someone press the pedal (or use a power bleeder) and crack all the lines at the master cylinder till they leak out a little bit of fluid. No bleeder screw, but it still works. When rebuilding calipers, it will take a lot of bleeding to get all the air out.

father2nate

Which order do you bleed the brakes on this car?

I went: Pass. Rear, Driver Rear, Pass. Frnt., Driver Frnt.

nine-44

It's a far thought, but it's happened. I know a guy that replaced his front calipers(non porsche car) and had a hell of a time bleeding it. I went to help him re-bleed the system and noticed he had the calpiers on the wrong sides, bleeders down!! Be sure the bleeders are on the tops of the calipers and re-bleed it starting in the rear(furthest away). Also, be sure that the calipers are sliding ok(I had this issue after a rebuild). Reset the calipers all the way retracted like you are doing new pads and pump them back in to be sure they are moving ok. I've seen them stick and only contact one pad giving a spongy pedal and diminished braking. Good luck

father2nate

Thanks... I will give that a shot. Yes, I did happen to install them correctly. (Upside-down, sounds like something I would do )

Peckster

[QUOTE=father2nate]When I finished removing the calipers, the master cylinder was empty. Air could have got in it then.

I did not measure the bores/pistons, but I clean them up with some fine sandpaper.

QUOTE]

The air that got in would be gone if you bled the system properly. Are you sure you know how to bleed a system?

You're supposed to use a hone for dressing brake cylinders, not sand paper.

theedge

Yes, quite correct.