jms 73

Soft pedal with no leaks - brake light comes on with excess pedal travel. Bled the brakes and pedal was fine. Found a bit of air in the right rear.

Drove the car for a day and the pedal went soft again. Still No Leaks

Bled the brakes again found air in the right rear again. Pedal was fine.

Drove the car for an hour and pedal is going soft again.

Master cylinder bad? Booster bad?

Please let me know your thoughts - Thanks

donyue

Hi jms 73,

I gather you have the stock calipers on your car? If so, the problem you are describing sounds like the caliper piston seals sucking in air.

This is a common problem with the stock calipers on our cars. Sooner or later most C3 corvettes will experience the issue.

You can rebuild your calipers with a upgraded piston seal type or you can purchase rebuilt calipers with the new seals.

Or you can replace the stock calipers with aftermarket calipers such as the Wilwood aluminium calipers.

Hope this helps.

jms 73

Great info Thanks

Makes sense as it seems to be that pesky right rear. I am assuming they are stock - I will check.

Much appreciated

Mike Ward

I bet someone swapped out the brake rotors and didn't check/correct the lateral runout. Alternatively, the rear bearings are shot and allowing the spindles to wobble.

Same effect.

jms 73

Mike

I am confused - How would rotors and run out effect the pedal feel other than a pulsation?

ddawson

The back and forth of the rotor cause the caliper pistons to cavitate sucking in air.

You may not feel it in the brake pedal. That sounds like your issue so get the rotor run out check and shim it.