1987 Fiero GT Brake Pedal To The Floor!!!!

[Jbar63]

Gentlemen,

I come here out of desperation! I started by replacing my brake pads and ever since then my pedal goes to the floor. Here are some facts.

1) replaced both rear calipers
2) bled all the way around multiple times
3) replaced master cylinder, twice!
4) disassembled and cleaned combination valve
5) bled more than 1 gallons worth of brake fluid!
6) no signs of leaks!

Gentlemen, what am I doing wrong? Should I replace the combination valve if I can find one or, simply drive it off of a cliff?!!! I'm in TX so that'll take some work!

Any advice you can offer is extremely appreciated!!!!

[Shaun41178(2)]

do you keep pushing air when bleeding?

[The Dark Side of Will]

You replaced the rear calipers... did you re-adjust the parking brake? A grossly out-of-adjustment parking brake can leave you with so much free-play that the pedal goes to the floor.

Also, have you tried moving the car? The booster on my dad's Datsun failed in such a way that the brakes had no feedback. They still worked... just no pedal feel at all. If the booster died the right way, it might give you pedal that "feels like" it needs to be bled.

Edit: Welcome to RFT!

[Jbar63]

Thanks for the replies!

No air when done bleeding!

Ebrake adjustment NO. I installed the calipers as they were straight out of the box! I assume these are set properly from the factory. I found no procedures concerning these emergency brake levers other than they need to be against the stops! Is there such a procedure I should be following???

Thanks guys!!

Jeff

[Jbar63]

So I checked the brake levers against the caliper piston travel. The brake catch within 1/2-3/4" travel of the lever.

I am at a total loss fellas. I don't guve up easily and definitely don't like getting my ass kicked! But I think it's time to take it into someone to figure out! Any other suggestions would be appreciated!

[ericjon262]

So I checked the brake levers against the caliper piston travel. The brake catch within 1/2-3/4" travel of the lever.

I am at a total loss fellas. I don't guve up easily and definitely don't like getting my ass kicked! But I think it's time to take it into someone to figure out! Any other suggestions would be appreciated!

try bleeding just the master. if it became air bound some how, then it won't be able to move fluid, and you won't be able to bleed air in the master through the line.

[Emc209i]

Did you bench bleed the master...?

If so, and done correctly, the most probable explanation is that air is leaking into the system. I don't know the condition your car is in. Are the lines rusted? Have any of the lines been replaced? Are any of the flare nuts rounded off from previous access?

When working with an old car, its a good idea to replace almost everything in each system to insure your problems don't stack up.

When working with anything built in America after 1970, its essential to replace everything on the car multiple times to prevent yourself from setting it on fire.

Why didn't you replace the front calipers at the same time?

[The Dark Side of Will]

Ditto... I had assumed you'd done the MC install correctly, but if you didn't bench bleed it, that could cause these problems. Do you bleed with the pedal? Do you get much fluid out of the calipers or just a tiny bit?

Ditto on complete inspection of all the lines.

[Jbar63]

Master cylinder bench bled properly, once on bench then again on the vehicle.
All four calipers push fluid with no air!

[The Dark Side of Will]

At this point, we're all going to be grasping for straws.

Did you drop the pusher out of the booster (so it's not making contact with the MC piston)?

Bad MC out of the box? Twice?

Quadruple checked for no leaks (hard to see leaks from the caliper piston seals & boots).

Do you get a LOT of fluid out of the calipers when you crack the bleeder screw, or just a little?

Is there a change in pedal feel when the pedal is pushed and you crack the bleeder screw?

[draven]

my .02 cents...

Purchase some block off brass plugs for your master cylinder and install them just after a bench bleed or proper elevated installed bleed. Depress the brakes. Test for firm pedal. Then remove the plug from the front circuit and connect, and bleed the front brakes and then try the same pedal test. If the pedal is firm the front circuit is good then hookup and bleed the rears and retry.

This should give you a pretty good idea if the problem is in the MC, the prop valve, the front circuit or the rear. I've had all manner of troubles with the e-brake rear calipers on the pre88 and 88's when they are old and worn. the above steps have helped me pinpoint the rears several times...

I've had two 88 MC's from NAPA, back to back, leak like a sieve out of front piston.