OK, my brakes get really hard to push one day and I could hear air leaking when I pushed on them, I replace the Booster and the master cylinder and I used a pressure bleeder to bleed the brakes... They worked great then yesterday I went for a ride on my favorite road... a nice twisty road though the trees with no houses and no crossroads. you cant really go fast becuase of all the turns but its fun... anyway on the way home my brake light comes on and the brakes go almost to the floor... I know the rear brakes arent working because brake stands were never so easy before....

I'm thinking that the combination valve (pressure regulator) is bad... and I am wondering if I can replace it with one that will allow me to disconnect the rear brakes when I want... I dont go fast becuase I have a CDL with all the endorsements and cant take the chance of getting speeding tickets but I do like to smoke the tires now and then and turning off the rear brakes (only for brake stand) would put less stress on the car... If I am wrong about the combination valve (pressure regulator) let me know.. thats the only thing I havent replaced yet...


[Modified by rjs82vette, 10:19 AM 4/3/2003]


[Modified by rjs82vette, 10:38 AM 4/3/2003]

 

I'd check for a serious leak or even loose bleeder in the rear system.

 

Although it's possible that the combination valve is bad...it's more likely air getting into the system. You should inspect the brake system before bleeding. This is accomblished by attaching a clear hose to each bleeder and pump the brakes while watching fluid go out through it. If you can't get clear fluid with no air bubbles to come out then you have problems...air coming into the system without leakage is usually due to the calipers...just replace them, or rebuild.

 

check you rotors for runout or warping.

I also have to recommend you go with the Vette Brakes & Parts type O-ring conversion.

This goes a long way to reduce/eliminate the air pumping if your rotor are in decent shape. The tolerances required by the OEM seals to endure properly are almost inhuman-certainly inhumane.

Others will agree Im sure.

O-rings = done deal

Brent....

 

Wouldnt air getting into the system allow the brakes to slowly get worse?... My brakes were working great one minute then not working at all the next... one push of the brakes and they were solid and strong the next push and they went all the way to the floor...and would barley stop the car...

 

check your wheel bearings all around for play. You were on a curvy road, which causes the bearings to rock from side to side. This pushes the caliper pistons back in the bore and causes loss of pedal.

Everybody talks about rotor runout, but loose bearings also cause runout and have even more effect on braking quality.

jim