Brake tech question; Residual Pressure valves

[Greg]

So I put disc brakes on my '48 CJ2a, upgrading from drum brakes. I'm still running my stock (rebuilt) master cyl. When I drive the Willys, after about 15 min the front brakes begin to retain pressure and stay 'on'. Drum brakes need a 10 PSI residual pressure valve, disc brakes need a 2 PSI residual pressure valve. So....

I still have the 10 PSI residual pressure valve in the master and was wondering if I can leave it and put a 2 PSI valve in-line, or will the 10 PSI valve in the master push thru the 2 PSI? I'm trying to avoid taking apart the master cyl again... but I think I'm going to have to. Anyone else messed with this?

I bought a 2 PSI and 10 PSI residual pressure valve from Summit Racing.... if I have to pull the 10 PSI valve out of the master, then I'll drop both of the valves in.

 

[I Lean]

You are right, the 10psi valve will negate the 2psi one....since it's maintaining 10psi in that whole section of line. You need to remove that, it sounds to me.

 

[Greg]

You are right, the 10psi valve will negate the 2psi one....since it's maintaining 10psi in that whole section of line. You need to remove that, it sounds to me.

Yeah, better to do it right the first time.... just didn't want to take the brake system all apart again!