I replaced my calipers and brakes and rotors i have a 87 GT and after i put eveything back in place my brake pedal was hard like it wuold hardly go down so i open up the cap where you add brake fluid and i can see that when i press the pedal it does shot a little bit of fluid up but my pedal is still really hard i took off the brake lines of the rear calipers those are the one i replaced and i get no fluid to shot out those lines in the back the lines are disconnected and the pedal is still hard and no fluid comes out the back lines. please help can it be the booster the car did need the brakes replaced thats when i notice the caliper on the driver side was not working but decided to replace both rear now i can make them work.

I re-read your post about 5 times and I am still not sure I know what you did.

It sounds like your brake booster is not working. Is the car running when you do all these things?

Sounds like you tripped the proportional valve next (under) to the master cylinder. There is a safety valve inside that is designed to cut off flow to either front or rear brake line in case you bust a line open while you're driving, that's so you can stop.

I tripped mine while working on my rear brakes so I opened up a bleeder screw on the front caliper (different circiut) and pushed the brake pedal hard and it reset. I'm sure that other will chime in here for you and properly articulate what I am trying to describe for you. It can frustrating, like in my own case, until you understand whats going on.

Never heard of that before. that's good to know

quote Originally posted by jetman: Sounds like you tripped the proportional valve next (under) to the master cylinder. There is a safety valve inside that is designed to cut off flow to either front or rear brake line in case you bust a line open while you're driving, that's so you can stop. I tripped mine while working on my rear brakes so I opened up a bleeder screw on the front caliper (different circiut) and pushed the brake pedal hard and it reset. I'm sure that other will chime in here for you and properly articulate what I am trying to describe for you. It can frustrating, like in my own case, until you understand whats going on.

Balance spool is just to activate the switch and bypass the prop valve when front brakes have a problem.
Once hydraulics are fixed, Balance spool should reset by itself. If not then spool has a problem.
Also rear bypass for prop valve uses a small opening and can be blocked with dirt/etc...

See my cave, prop valve in brake section.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave (It's also at the top and bottom of every forum page...)

Did you start the car?

Once you pump out all of the vacuum of the booster, the brake pedal will feel much higher and much harder than with the car running.

I did start the car and i have done brakes before in the past but the first time replacing the calipers and like i said car on or off the brake pedal is hard it hardle goes in when i press it and i have the rear brake like disconnected to see if i get any fluid to come out i figure with the lines off the pedal would come down but it doesnt.

Turn your car to ON, but not Start, to see if your brake light is good. If it is not, replace it. Then start your car and press the brake pedal. If the light comes on, your "balance spool" has tripped. With all brake lines connected, try pressing the brake pedal very hard to see if you can reset it.

Sometimes the valve can be centered by cracking a bleeder on the other side (ie the rears) and depressing the pedal. Sometimes you have to take out the switch and move the piston by hand. Worse case is to pull the piston assembly out the side nut. Even worser is just to replace the damn thing with one from a junk yard.

https://www.fiero.nl/forum/Forum2/HTML/102353.html

[This message has been edited by phonedawgz (edited 10-03-2011).]

wow i never knew any of this thanks alot everybody.