Swapping proportioning valve for "T" fitting... Options

[Wanna9146]

I read on this forum recently about someone swapping out their proportioning valve for a "T" fitting.

Does anyone know the size/thread count of the correct "T" fitting? Any fabrication required?

[r_towle]

The proportioning valve is really a simple piston and spring.
I have never met a bad one.

If you still have mushy brakes its because you have not bled the air THROUGH the proportioning valve.
This is not as easy as it sounds.
the spring requires 750 PSI to activate, and most people dont get that when bleeding brakes.
It can be done using the old school two person brake bleeding system, but honestly I have never had success with that, nor a power bleeder, nor a miti vac bleeder.
The reason I suspect that I have never had success is because I am the bleeder, not the pumper.
If I was pumping, I would pump them till they were firm and then try to push the pedal through the floor...that will do it.

The only way I know I have rid myself of the nasty bubble is to bleed them the best I can, then go for a ride and STOMP on the brakes about ten times...this produces the required PSI to move the air past the valve.

Then I go home and bleed them again, and I am all set to go.
Be careful because when you finally get the air bubble past the valve, it will feel like you have almost no brakes at all...pedal to the floor.
I stay close to home...its a ten minute ride.

Rich

[davesprinkle]

The proportioning valve is really a simple piston and spring.
I have never met a bad one.

If you still have mushy brakes its because you have not bled the air THROUGH the proportioning valve.
This is not as easy as it sounds.
the spring requires 750 PSI to activate, and most people dont get that when bleeding brakes.
Rich

Rich, respectfully, you're wrong about this. The proportioning valve doesn't OPEN under high pressure, it CLOSES. This behavior has the effect of clamping rear brake pressure while still allowing front brake pressure to rise.

I agree though, that the p-valve traps air.

Want my input? Use the long-hose bleed method. It worked for me and it kept the wife out of the garage. No high-effort stomping on the pedal required.