brake proportioning valve leaking

[1971ford]

I drove home from a buddies when all of a sudden no brakes.
Looking at it now its because all hte brake fluid drained from a bolt at the top of the proportioning valve. I have no idea what this bolt is for except to piss you off. And it's doign a fantastic job.
the fluid is coming out between the bolt head and the block. It was still cranked down hard. I took the bolt out, went to the auto parts store and got a copper crush washer and put it back on, cranked it down as hard as i could.

Guess what it still spews fluid out! Fantastic!

What is the problem? I have no ride right now...

[fireguywtc]

I am assuming this in your 71? I am not sure what to tell you except it may be the bolt that contains the small valve that detects the varying pressures in your system for that brake light in the cab that hardly anyone really uses. But it is difficult to say for sure without a pic. I am guessing your valve is different then the one on my 67? I know you are probably too busy atm for pics. Perhaps some teflon tape or a regular bolt can get you buy until you can get ahold of another bolt or proportion valve.

[fordman]

isnt it a paper gasket that goes on the brake valves?

[1971ford]

Yes it's the '71 f250, dual piston discs up front, drums rear.
it might actaully be the distribution block. whatever the one is that is inside the frame channel under the steering box. has a plug and wires going to the brake warning light like mentioned.
2 brake lines go in the front and two out the back. It's a brass color.
There is a stupid bolt going into the top of it that is only 1/2" long but it's a 15mm bolt (no other size fit it) so it's not very small.

I was going to swap the valve/block whatever it is with another from the junkyard but im really sick right now and i can't even get my own off. of course all teh rbake lines are stripped.

I took the bolt out and the top of the block/valve feels fine and the bolt surface that contacts the block looks fine. I went and got a copper crush washer and put it back on, and tightened it down as much as i possibly could. Pressed the brake pedal and it spews out between the block/valve and the bolt somehow. There must be RIDICULOUS line pressure. But i guess that's normal.
So pissed right now at this damn truck.

[1971ford]

This is NOT looking good.
One of the brake lines is completely stripped to a circle and not accessable with vice grips. The other line isn't even accessable with a line wrench.
Looks like the truck is going to be down for atleast another week....

[1971ford]

Stumped every one? Oh great master Keith? What could cause a leak at the top bolt when it is cranked down with a crush washer very tightly...

[FORDification]

OK, first of all we need to ascertain exactly what part you're dealing with. You mentioned that it had wires going to it, however, which means it's the distribution block and not the disc-brake proportioning valve.

Here's the factory distribution block, used with both drum and disc brakes:



Bumpside trucks that came with disc brakes ALSO had a proportioning valve that looks like this:



If someone (or you) have added the disc brake setup from a dentside truck, the dentside-era proportioning valve might have been used, and it looks like this:



The problem is....AFAIK there shouldn't be a bolt on top of any of these. So tell me which of these pictures looks like the part you're having problems with, and we'll go from there. (A picture really would be great!)

[1971ford]

Thanks! It's the top picture!
That's exactly it. You see the bolt on the top of the block (It is on the right side of the block in the picture but when it is mounted, that bolt is on top)? THAT stupid thing.

[1971ford]

Just to be clear I circled and labeled appropriately.

The green stuff is the brake fluid

[FORDification]

That's not a bolt...it's a brakeline fitting, or at least it's SUPPOSED to be.



1 - Out to rear brakes
2 - Out to left-front brakes
3 - Out to right-front brakes
4 - In from rear master cylinder reservoir
5 - In from front master cylinder reservoir

[1971ford]

okay... this is just weird.

How come my brakes worked great for the past several years missing a brake line? I'll have to go check how my truck's brake lines are plumbed right now. Time to get down and dirty late at night with a flashlight... because i can't stand the weirdness.
Any ideas?

Just too weird. It just started leaking now. It has never had a line coming out of the block in the past years i have had the truck. Someone jack my brake line?

[FORDification]

If someone stuck a bolt into #3 to serve as a plug, then they'd almost would've had to tee off #2 somewhere to feed both front brakes. Follow the two front brake lines and tell me where they go.

[1971ford]

Okay so my #1 goes to the rears like normal.
#2 goes into a T fitting deal that splits to both front brakes. It looks like your second picture. I'll go double check to see if its exactly that.
#3 don't have
#4 goes to rear reservoir
#5 goes to front reservoir

[1971ford]

just double checked and my #2 does indeed go to the front engine crossmember where it goes into that exact proportioning valve (your second picture) where it splits to both front brakes.

So is this setup all wrong? where is the proportioning valve suppose to be then?

[1971ford]

please excuse the gnarly grease. It's from the old power steering box that i have since swapped out that had a gnarly leak... and from this little problem we are discussing...