My brakes suck !!

[10secgoal]

Alright. When I got my car running, i tried to build boost of the brakes. I smashed the pedal, I mean I smashed it. I felt a tiny pop in the pedal. Ever since then the pedal goes down to an uncomfortable, unacceptable level before it grabs. I replaced the MC, thought it may have gone bad. Although it would hold pressure, and not lose it. After the install of the MC I thought maybe there was still some air, but just didn't feel like it. Maybe the slack adjusters are out. But they are all new out back. I just did the granada swap. Re-bled the brakes, and I get the same thing. If this was happening only aftert the swap I would think I just need a bigger MC.


I also flushed out all the old fluid with a vacuum bleeder. Got out all the fluid, but wouldn't bleed correctly. Was a waste, taking that junk back.

Any ideas here guys ?

 

[rbohm]

have you checked the wheel cylinders in back? its possible that they are causing the problem.

 

[10secgoal]

What exactly would I look for ? They aren't leaking.

 

[69 Rustang]

Last time I had a loud pop and felt the pedal go down I had exploded a front drum. That was a fun ride...

I would look for something wrong. Not sure where the problem is but I would have started at the master cylinder too. Assuming it is working, here is what I would try:
1) Jack the car up and spin wheels one at a time--then have someone depress the pedal to see if they stop immediately
2) Pull the rear drums one at a time and look everything over real closely
3) Have someone apply a little pressure and release to watch the action of the rear shoes (but don't push too hard) to see if everything is working as it should?
And I guess based on my experience of an exploded drum--look for cracked drums that have not come completely apart.

 

[10secgoal]

Hmmm, that makes alot of sense.Alot, but I hope not at 88 bucks a piece. They have about 150 passes ont hem. But only 300 street miles.
Any other ideas?

 

[xoxbxfx]

i agree...check all the cylinders in teh brakes. Same thing happened on my buddy's s10 the other day. The right rear cyl exploded and the pedal went straight to the floor

 

[12sec67]

maybe you need new drum brakes for the rear since your bad axle seal may have soaked your drums shoes to the point they're not grabbing. if you try that and still nothing then i would guess that you would need new rear wheel cylinders... luckily they're not to expensive and you should have a warrenty on the shoes- just chip a piece of the shoe off before taking them in.

hey 10secgoal- you left before i went for my test drive after we installed the porportioning valve-much better!

i went down the road and eased on the pedal and the fronts locks up before the rear like they are supposed to.

 

[10secgoal]

The seal has nothing to do with it. They grab fine. But they just go down too far BEFORE they grab. Plus the seal just happend when I did the gears. The brakes have been a problem longer than the seal.

 

[ForceFed70]

So you already replaced the MC and it made no difference?

The MC is the only place you could be loosing pressure without leaking fluid.

But your problem sounds a little different. Sorta like air in the line. I know you know you stuff... but everyone makes mistakes....you sure you bled everything properly? Bench bled the MC before installing..then bled the brakes?

If it's not air in the lines, or the MC... and your not leaking any fluid... the only other thing I can think of is poor lines. Could you have busted the braid on one of the lines allowing the line to "balloon" a little when under pressure?

 

[10secgoal]

I'm not atually loosing pressure per say. I put the pedal down, when it stops, that's it. It won't go any farther. Works like normal and the pedal stays put. It just goes down real far. The lines are OK, checked those yesterday when we re-bled. MC was bench bled.

 

[12sec67]

i had to fight with 10secgoal just to bleed his brakes!


that's funny--you asked him about the bench bleeding

 

[180 Out]

Did you rebuild the rear brakes as part of the seal repair? If so, my guess is they're not adjusted tight enough.

 

[rbohm]

I'm not atually loosing pressure per say. I put the pedal down, when it stops, that's it. It won't go any farther. Works like normal and the pedal stays put. It just goes down real far. The lines are OK, checked those yesterday when we re-bled. MC was bench bled.

check the pedal support. you may have broken something there

 

[SoCalCruising]

Do you have an adjustable pushrod for your MC? If so and everything else is really okay, lengthen the rod a bit at a time until you get engagement where you want it. Also, and before you do that, check the plastic spacer that goes on the top end of the pedal and over which the pushrod assy fits. Could you have broken it (loud POP sound)? Just a thought.

 

[10secgoal]

We adjusted them pretty tight when I fixed the seal. Too tight, they were reall hot when i got home. Still sucked. Socal, it's not adjustable.It's a 67 stocker. I'm gonna put in an adjustable porp valve, and a new master. Prolly from a granada or maverick. Something with a bigger bore.RBOHM, I'll lokk under there when I'm stuck on floor. t's a tight fit. Some good ideas, gonna try them