Brake problem

[tcolyer]

I have a never ending problem with my brakes, can someone shed some light?

I have an 82 Corvette with 78,000 miles, I have replace everything a least once.
4 different mastercylinders, brake proportional valve, brake booster, All stainless steel lines, two different rubbers hose sets, three different sets of calipers (rebuild originals, Florida caliper rebuild originals with o-rings, originals with VBP pistons & o-rings & new springs, and now a complete set of VBP o-ring calipers.

I have tried all different ways to bleed the system, gravity, vacuum, pressure with someone pumping brakes, now a pressure bleeder from Mid-America.

I still have in my opinion have poor brakes, pedal low, torque transmission at 1500 rpm and the car moves off very easily with brakes applied.

Can some one help.

Terry Colyer
(cell) (615) 238-5069

 

[Twin_Turbo]

Did you bench bleed the MC? What is the condition of the vac booster? How is the rotor runout? I assume you properly bled the system using a vac or pressure bleeder is a good idea.. ????

 

[tcolyer]

Yes, I bench bleed the M/C and even unbolted it and placed it level during the Pressure bleeding, The booster is new just bolted on. Rotor run out is OK, but brakes do not feel good before I start rolling, so run out is not a factor.

Any help is apreciated. Thanks Terry

 

[Twin_Turbo]

It can be only a couple of things, leaking caliper(s), air in the system or an internal leak in the MC. I guess you have checked the calipers for leaks so they should be okay, one of the MCs should have been okay so that would pretty much rule that one out. So the thing that would probably be causing this is air in the brake lines.

Not trying to be a smartass here but are the bleeders on top of the calipers? I have seem the calipers mounted on the wrong sides one time and the owner couldn't get his brakes bled because of it.

Is your MC fluid level constant?

 

[chrisgen3]

Sounds like my Corvette.

Did you fix your brake problem? I would be very interested if you found a solution. I have an '80 with problem brakes. I have yet to maintain a good pedal height. With time it eventually approaches the floor and I have to bleed the brakes again. I'm hoping for some insight.

I have a never ending problem with my brakes, can someone shed some light?

I have an 82 Corvette with 78,000 miles, I have replace everything a least once.
4 different mastercylinders, brake proportional valve, brake booster, All stainless steel lines, two different rubbers hose sets, three different sets of calipers (rebuild originals, Florida caliper rebuild originals with o-rings, originals with VBP pistons & o-rings & new springs, and now a complete set of VBP o-ring calipers.

I have tried all different ways to bleed the system, gravity, vacuum, pressure with someone pumping brakes, now a pressure bleeder from Mid-America.

I still have in my opinion have poor brakes, pedal low, torque transmission at 1500 rpm and the car moves off very easily with brakes applied.

Can some one help.

Terry Colyer
(cell) (615) 238-5069

 

[JohnZ]

If your pedal gets progressively closer to the floor over time (with driving the car, not just sitting in the garage) and there are no leaks anywhere, air is getting into the system, most likely due to rotor runout causing "air-pumping" past the piston seals. This usually occurs at the rear calipers; if you haven't had work done on the rear rotors, it's usually rear wheel bearing play beyond spec, which causes the rotor runout, even with good rotors. When you bleed the brakes, where do you get the most bubbles - front or rear calipers?