Yet another rookie question...I was wondering what the Proportioning Valve does. I located it (at least I think I did, see picture) and it looks like there used to be a wire connected to it. Should there be a wire connected to something? I've been driving the truck for about two years and I'm not sure the wire was ever connected while I drove it. The truck has the stock drum brakes and is manual braking. Several months ago I had a mechanic replace the master cylinder and check the pads and springs and he didn't mention anything. I've read a couple post and it seems like the Proportioning Valve is for disc brakes. I rewired the truck with a Painless harness and the only wire designated for the proportioning valve is in the underdash area and certainly not long enough to get anywhere.

 

The proportioning valve is used in all brake systems for the most part. The wire is used to light up your "brake" warning light on the dash when it senses a drop in brake pressure to the front or back. There is a valve inside that block, and if it moves to one end or the other, it turns the light on to let you know there is a problem.

Even if the light is not hooked up, when you have a brake issue, you'll feel it in the pedal anyway(low pedal or goes to the floor).

 

Thank you Freightrain for your great response. It's nice being able to understand more about my truck.

 

Well, actually it isn't a proportioning valve but a distribution block. Ford didn't put proportioning valves on vehicles until much later and this '67 has a distribution block. This is from Inline Tube......" Although very similar in appearance to a proportioning valve, the distribution block does not alter brake line pressure. The distribution block keeps front and rear systems separate, splits the left and right front lines and houses the sending unit for the brake failure warning light." Proportioning Valves
Freightrain is correct about the light tho.

 

Quote:

Originally Posted by 67F250RET

Should there be a wire connected to something?

C7AZ-2B264-A .. Low Brake Fluid Warning Lamp Switch ~ Threads into "Brake Pressure Differential Valve" / All 1967 only FoMoCo vehicles.

The valves used in 1967 F100/350's are also 1967 only and there are THREE different types.

 

Thank you guys for the additional info, I'm the lucky guy who bought a 67 without knowing it was pretty much a one off year for a ton of parts. Good times!