Where to find a brake pressure differential valve.

[farmtruckman]

Sorry to duplicate questions, but I should have looked at this subject first. I have a brake lite showing and was given a response of

"Probably need to adjust the or center the valve in the proportioning block" which I appreciate. My problem is how do I adjust or center the valve. Also, I have a 67. Any thoughts on where the valve even is?

Thanks for the help.

[fordman]

it should be on the frame under the front of the cab.

[farmtruckman]

Thanks for the location. Any idea how I "adjust or center"?

Thanks again.

[frisky]

First I have to admit I have never had to do this...

The spool moves and turns on the switch because more fluid went to one end of the truck then it did to the other and indicates a major leak somewhere. It can also happen during bleeding. So first, make sure you don't have a leak to attend to.

but if I recall, the procedure is to loosen the line at the valve or manifold opposite of the side the fluid leak out and then use a careful amount of movement on the brake pedal to create brake fluid pressure to move the spool until the light goes out. Go slow, if you move it too far the light goes off and on and you have to tighten up the line and do it over from the other side.

I am pretty sure a service manual will have this procedure in it as well.

Be sure to tighten things up and check for leaks...

[FORDification]

Read the following thread:

http://fordification.com/forum/viewtopic.php?t=2214