Just bled the brakes on my ‘97. I used the one-person method with a clear hose going from the bleeder through a clear hose into a bottle placed above the caliper. I kept reservoir full. Pedal is good and firm when engine is off. With engine on the pedal sinks to the floor when pushed with no resistance. Springs back up okay.
The hand BRAKE light is always illuminated even when it’s not up.

Pulling the hose off the booster gives me a hissing noise with vacuum and the rpms go up, seems normal.

No leaks from lines or calipers.

There is some fluid leakage on the master cylinder mounting bracket. Seems like it’s coming from behind the bracket itself.


What is this most likely coming from? Master cylinder or booster? I don’t want to have to blindly replace parts. I could try bench bleeding.

 

Master cylinder isn’t holding fluid pressure, with engine running press the brake pedal 3 times and see if it holds, if fades away to the floor your master cylinder needs to be replaced. Correction press the brake pedal 3 times then start engine, see if pedal fades? If it fades your master cylinder has failed.

 

In addition to the correction if the pedal fades and holds pressure and doesn’t go to the floor it’s working correctly.

 

I went through 2 master cylinders over 3 months until I got one that worked Ok, still had a low pedal but it held good.

 

Yep, it was Master cylinder failure. Some Gasket must have failed inside making it leak. Just bled the cylinder and each caliper. Went in sequence: LR, RR, LF, RF. Squising noise disappeared after LF.

 

I had my 97 in a shop to install the Master cylinder and I picked it up the following morning. No brakes... They said the just drove it out of the shop and they worked fine. those off brand MC can be tricky.

 

Luckily, I got a nice TRW brand master cylinder off of P.T. Schram. Didn’t even want to mess with any other brand the auto stores were offering. I‘m guessing TRE made the original OEM because it looked exactly like the one I swapped out.