Question: brake pedal

[chuck roast]

Need information! I bought a 76 that has been sitting for about five years, the driver side rear caliper was leaking so i bought a new one and installed it. I never had any pedal to speak of but i thought that was because of the bad caliper. Now i still can not get any pedal but the car stops. Can any one help

 

[6880 Mike]

If one caliper was leaking, it's reasonable to assume the other three are also leaking. Check for leaks on the other three corners. Check the master cylinder. Is it gunked up?

Bleed the system again. Remember: on rear claipers, bleed the inner halves first, then the outer halves.

 

[chuck roast]

I did check the other calipers and see nothing leaking. When i check the master i don,t have any loss of fluid.

 

[JohnZ]

Do you get any pedal when you bleed the system completely?

 

[chuck roast]

Thanks for the reply johnz but I never bled the whole system. but i have been told it could be the vacume boster. let me know your thoughts.

 

[minifridge1138]

I suggest bleeding the system and trying again.
Bleeding the calipers is easy, but i believe there is a trick or two for bleeding the master cylinder.

Good Luck and let us know what you find out!

 

[6880 Mike]

...I never bled the whole system...

Boosters seldom fail and usually don't cause Corvette brake problems. Bleed the entire system.

 

[White75]

Bleed the entire system. If you still get no pedal, replace the MC.

 

[Bob Chadwick]

I never had good pedal on mine until the master cylinder went out and I replaced it.

 

[chuck roast]

How sure are you on the master cylinder? Is there a way to test the master cylinder, and does the master cylinder have to be on or off the car?

 

[Curtis]

If you have properly bled the brakes and have no fluid leaks anywhere, then the only other place to lose pressure is in the mastercylinder with the pressurized fluid going back past the plunger.. It is a $40 part. Replace it.. Bench bleed the master cylinder before you install it on the car and your job will be a lot easier.

 

[6880 Mike]

...Is there a way to test the master cylinder, and does the master cylinder have to be on or off the car?...

You can visually test a master cylinder while it is installed. Do you see any brake fluid leaks around the bleeders, fittings, or the rear of the master cylinder? Is there brake fluid on the lower front and bottom of the booster? Does the area directly beneath the master cylinder look like brake fluid has been dripping on it? Run your hand or a rag along the underside of the master cylinder. Get any brake fluid on the rag? Open the top and look at the condition of the brake fluid in the reservoirs. It should look like regular brake fluid. If it appears rusted or crudded up, it is. Can you see the bottom of the reservoirs through the brake fluid?

If you find evidence of leaks or if the reservoirs are gunked up, you can reasonably assume the master cylinder needs to be replaced.

If your master cylinder is an original and if you want to keep it installed for judging purposes, there are professional rebuilding services available.