VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans Proportioning valves for 1950 3100?

Howdy,
Jumping back in the ring on a subject I have investigated before, but never gone this far. We are converting over to a dual master cylinder on our 1950 3100, and are wondering about the proportioning valves that are needed. Might anyone know what size/shape/flavor will work for this conversion? Or better yet, where to find them?

Thanks!

Just following this up...
I spoke with the Filling Station, and they told me that I needed a "two pound valve" for the front brakes and a "ten pound valve" for the rear brakes, which they had in stock. Has anyone had any experience/problems with these valves on a similar truck?

Thanks!

Hey Ben. Question for you. What type of brakes are you running on the truck? I'm curious as to why you're putting a dual M/C on it. I've got a '50 PU with the original Huck brakes, but plan to update to Bendix in the future. Both of those set-ups only require a single master cylinder. Curiousity has gotten the best of me.

Ken

One is not needed if you are keeping the drum mbrakes,just get a master cylinder for drums and you should be fine,I put discs on my 37 and did not use one and the brakes work great but I did put residual valves in since I did not know if the disc master cylinder had them.

Jeff
You should not have residual pressure valves with disc brakes but need them for drum brakes. The reason is the disc caliper seals retract the piston as the hydraulic pressure is released where as the springs in the drum brakes do the releasing and the seals (cylinder cups) require light pressure to maintain their pressure on cylinder wall.
Tony

I was worried the master cylinder would be lower then the brakes since the 37 is lowered a bit so I installed then since I was not using a proportioning valve,I just have the discs on the front and seem to work just fine they way I have them.

Ken,
We are keeping the drum brakes on our truck. We have been asked this same question before, as many folks are confident that a single master set-up should be fine. However, as we plan to change the rear end ratio and do a fair bit of highway driving, my father-in-law has insisted that we go to the dual master if I want my wife riding in the truck. Can't really argue with that!

Ben

Ben, far be it for me to argue with logic like that! Best of luck with your rebuild! SWMBO always comes first!

It is a common misconception that dual master cylinders will not completely fail but you will only lose braking either in front or back. Let me dispel that myth. If the problem is in a wheel cylinder or brake line then you may have functioning brakes in the other end. But if the proportioning valve or master cylinder is defective you can have NO BRAKES. Been there done that.