Proportioning valve
 

Does anybody have an idea as to where each brake line goes on the proportionoing valve? I'm not sure I got it right. Thx for the help... Kevin

Re: Proportioning valve
 

Are the lines not pre-bent for the unit? I know there are two or three 1/8" lines and two or three 3/8" lines right?

Re: Proportioning valve
 

The prop valves on 73-87's attach on the splash apron in front of the motor. Looking @ the motor....
The outlet on the side facing the driver frame rail is the front driver supply.
The outlet on the bottom of the p-valve is the pass front supply.
The outlet facing the pass side frame rail is the rear line supply (one common line that splits @ the rear axle).

The inlets from the master cyl are the 2 ports at/near the top of the p-valve.

Re: Proportioning valve
 

Anyone have a clear pic that we could add the this info? It would make a great 73-87 FAQ.

Re: Proportioning valve
 

This is a quick pic , I really think a trip to the salvage yard would be better .

1984 C30
Attachment 743610


1984 K20
Attachment 743644

1974 K10
Attachment 743645

Re: Proportioning valve
 

Working on it.

Re: Proportioning valve
 

Thanks....

Re: Proportioning valve
 

Those are excellent pictures guys. thanks alot... Kevin

Re: Proportioning valve
 

1) Front pass side
2) Front driver side
3) Supply from master cyl to fronts
4) Supply from master cyl to rear
5) Rear common

Re: Proportioning valve
 

Thanks to Scot, Dave and all involved. This will soon be in the FAQ forum.

Re: Proportioning valve
 

Scoti, do you know the typical size fitting for #5? I am running all new lines, front is done, and I have the rear set up but my 3/8 fitting does not seem to want to screw into the #5 port? Threads look fine on the Prop valve. I did pick it up from a yard, and the external fitting is brand new. Also, rear line is 1/4 inch, stepped down form the 3/8 fitting... Sorry to steal the thread, but could be helpful here too I guess... :lol:

Re: Proportioning valve
 

It is an 'odd' fitting. I do have the exact size but don't have the info in front of me. I'll get it for you & post it up once I have my 'notes' in front of me tonight.

Re: Proportioning valve
 

Thanks Scoti, I appreciate the help!!

Re: Proportioning valve
 

That rear fitting is a 9/16-18 port to a standard 1/4" Domestic brake line.

Re: Proportioning valve
 

Thanks Scoti, now the search for the fitting!:lol:

Re: Proportioning valve
 

I've found short pieces of line w/it attached @ Oreilly Auto Parts (<$5) or in a 10 count pack @ Advanced Autp Parts; zilch elsewhere. I had my fitting re-plated to match the remaining fittings.

Re: Proportioning valve
 

Ya, looks like a very odd fitting. Thanks for the tips!

Re: Proportioning valve
 

Something like this?? Amazon.com: IMPERIAL 90171 CYLINDER BRAKE FITTING...
well so much for that working...

Re: Proportioning valve
 

This Pic helped me:
http://i1106.photobucket.com/albums/...achment-40.gif

Re: Proportioning valve
 

Just found this at another forum:
http://i1106.photobucket.com/albums/.../292038479.jpg

Re: Proportioning valve
 

pasted:

Re: Proportioning valve
 

Here's the fitting needed to connect the 79 chevy truck's rear port of the combination (proportioning) valve to the 60-66 brake lines:
http://i1106.photobucket.com/albums/...5/IMAG0721.jpg

http://i1106.photobucket.com/albums/...5/IMAG0717.jpg
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Posted via Mobile Device

Re: Proportioning valve
 

This weekend I swapped backing plates from 11" to 13" on my 9.5" 14 bolt, do I need to swap proportioning valves?

Re: Proportioning valve
 

Just an fyi for some who are looking for this fitting.... I found it at autozone. I looked all over on-line, napa, etc. Check autozone or orielly's if your having trouble.

Re: Proportioning valve
 

You might need to verify you have the correct wheel cylinder for the brakes. They use different wheel cylinders for the C10's standard 2"w vs the HD 2.75" w drum brakes so it might be worth verifying.