Brake priority valves

[Todd]

I have replaced all the rotors, calipers and mastercylinder and I am unable to get the rear brakes to bleed out. I still get a brake light. Is it possible to reset a priority valve?

 

[bill81vette]

I don't know about your year vette but mine has bleeders in the inboard and outboard side of thew rear calipers.....

did you bleed both sides????

 

[JohnZ]

I think you mean the distribution block, which contains the differential pressure switch; it's just a spring-centered spool that grounds the warning light circuit, and it shouldn't "stick" unless it's corroded inside. If it is stuck, you could close the rear bleeders, open a front bleeder, and kick the pedal to move it back to center.

 

[duke94]

Make sure the parking brake switch is off. It shares the same light with the valve.

 

[Todd]

Priority Valve

Thanks for the info. It is a proportioning valve, my mistake. I will remove and inspect.

 

[Vettehead Mikey]

It's not a proportioning valve, those didn't appear on Corvettes until 1978(?)

Yours is a distribution valve ass'y as John said above. There's no mechanism to proportion or limit brake pressure. Big difference!

 

[GerryLP]

On the L81's, I believe that the manual says that the light will extinguish it self once 400 lbs (approximately; I can't remember the actual setting) of pressure is sensed.