Hello all, I read every post that i could find in this area regarding my problem but I'm just hoping that i missed something.
My FC's break peddle goes to the floor like air, when it finally engages the break it does it so hard that I'm expecting to go through the windshield any time now.
I send the '89 to a trusted mechanic for the past 5 years and he treats the car with reverence (as it should be). So far he has tried 2 new master Cylinders .. he has bled it by the book 4 times and the same problem exists. He says that when the car is not running the break pedal seems feel fine. After it starts it’s right back to the floor.
Plenty of pressure in the lines, new booster, pumping does nothing. Everything has been replaced except the Proportioning Valve which he doesn’t believe is the problem.

I’m open for any suggestions that I can bring to him and I appreciate your time and thoughts.

Munz

 

Sounds like the booster or a vacuum line connected to the booster. Do the simple test yourself as outlined in the FSM.

 

did the large vac line to the booster get replaced recently???

 

check your hoses, make sure you dont have any breaks in them. Do break pedals have slave cylinders as well like clutchs? if so that may be your problem.

 

What kind of a question is that? "Break" pedals don't have diddly. Brake pedals are connected to the master cylinder and the only "slave cylinders" in the brake system are the calipers or wheel cylinders. I know you are trying to help, but I would suggest that you learn a little more about these cars before offering up advice. Read, read, read! Listen, listen, listen.

 

*sigh* okau here's the deal, everything was checked a total of 4 times and i still have the problem. We went through 3 master cyl's and it still appears to be the problem, but having 3 bad ones seems highly unlikly. Since i live in upstate NY and the snow can hit anytime the car is being tucked away for the winter and come spring she's going to a dealer. I wanted to thank you all for your help and attention though. If it turns out to be something really weird i'll post here what happened so none of you end up with the same problem.

Thanks again for your assistance

Munz