PorscheZen

For a '90 C2: When I pump the brakes, it does not get the pedal to firm up.

Just got car back from shop. New pads and rotors all around. Had system flushed as well.
The thing that bothers me is that the pedal goes about 3/4 to the floor and seems to have 2 steps in braking. In the first step, the brakes grip but only lightly, the second they grab more.
I was expecting/hoping that with all the new brake componants, the pedal would be firm. I've read a number of threads suggesting numerous things but thought to ask this specific question and see what comes.

Does the '90 C2 have a Master Cylinder which can be bled? How would I go about bleeding the hydraulic accumulator/brake booster?

1990-964

It sounds like you air in the brake lines. A thorough bleeding should fix the problem. You accomplish the bleed at each brake caliper not the master cylinder. That said if you just got the car back from a shop that performed that work I would hold them accountable and try to make them fix it properly. Good luck

LouZ

When I was a P-car novice a few years ago, I bled the brakes and ended up with a very low pedal. I was nearly convinced that the master cylinder was a goner! Our fellow RL forum gurus suggested that the problem was air in the calipers. When I reported back that I rebled all again, doing 1 bleeder on each caliper, I was "advised" that the front calipers have 2 bleeders each (the second one in the inside portion is a bit hidden). Well, as I reported back, it burped air like a drunken sailor from the inside bleeders. Then the brake pedal was solid.

jimq

if you have the updated calipers on the rear (4 pot) instead of the standard 90 (2 pot) they also have 2 bleeders.

JasonAndreas

Were you experiencing this problem before the brake job?

It does (blue arrow in the image below) but you only bleed it when replacing the unit.



The C2 does not have a hydraulic accumulator, the system operates on vacuum assist. Assuming this is a new problem I would take it back to the shop and have them bleed the brakes again. Otherwise go out and buy a Motive Power Bleeder but whatever you do, do not try bleeding the system with the brake pedal method or you will probably end up requiring a new master cylinder.

PorscheZen

Thanks Jason...ah,er, I mean Spicoli
Actually I think I was going to do exactly what you recommend. Re-Bleed ( have a PWR Bleeder) and see. I kind of expect the MS to be shot. Long story. Cooked my brake fluid at Watkins Glen late last year and had some "track techies" help me out to bleed by the pedal pump method. Really, my brakes have never been the same since... If I have to purchase the MS, i'm thinking of changing to a 993 MS. However, can't locate Viper Bob's contact info about the conversion kit which takes into account the difference in tube diameters between the old and new systems.

jeffnudd

I experianced the same problem and yes just like the guys said 2 on each caliper, made a big big difference, however because i drained my system i did have to also bleed through nipple on the master cylinder to make sure of no air and then bleed up the calipers.
Bleeding the master cylinder did make a huge difference.

Edit: Because of your new brakes it may take sometime for everything the wear in, in time that will make a difference but not a huge difference.