Brake Combination (Proportioning) Valve

[motormayhem]

So mine started leaking from where the rear brake line connects to it. I took it apart to clean it and hopefully get it to seal up so I wouldn't keep getting air in my rear brakes. Long story short I pinched the seal inside and it got tore apart when I put it back together. Where can I get a new valve or a rebuild kit or the seals for this thing? I'm talking about the valve right on the front crossmember.

 

[Sharecropper]

The proportioning valve is no longer available through normal parts sources. The only thing you can do is to obtain a replacement valve off a parts truck. There are several guys here on SS which have parts trucks. You may want to run a Parts Wanted ad in the classified section of the forum.

When you re-install the replacement valve, make sure the little dot is positioned at 12:00 when you reinstall the arm. I posted some photos in post #75 of my rebuild thread.

Hope this helps.

 

[motormayhem]

I'm talking about the valve under the front crossmember that can set the brake warning light on. Is that one out of production?

 

[Sharecropper]

No, I misunderstood. My comments were regarding the rear proportioning valve.

My Bad, sorry.

 

[Warthog]

The front unit is also out of production. Used is the only option that I know of.

You might find an aftermarket from some place like Summit.

 

[KevinPD]

Hey motormayhem n others, Will a used part from a CUCV tha burned up work? Can they be rebuilt? There is a junkyard in Pepperell Mass(Wilsons) that I get some parts from thier K5s and this sadlt ended 09 off of.I could pull it and send it to you or you could call them up ,as a last resort if nothing else works. I know they're on the "Net cause my boss had me go there to get a bumper for one of the work trucks I work on at the shop..or call me at 603-222-2099 if you need it.

 

[ranger1950]

My valve started leaking also. Got a new valve from Carolina Classic Trucks. Direct replacement and works fine. Make sure you get the tool that screws into where the switch goes. It will keep the spool from moving when you bleed the brakes, then put the switch back in. They have a website. Hope this helps.

 

[Barrman]

Thank you very much for posting this. Here is the exact link for anyone needing one.

https://www.carolinaclassictrucks.com/78-87-GM-FS-Truck-Prop-Valve.html

 

[richingalveston]

They state it is for front disc and rear drum, wonder if it is a problem when you converted the rear to disc.
Mine is currently removed from the truck and looks pretty bad, was considering replacing it.
I assume this is same as stock and since my current one is stock and working with the current rear disc, the new one would work with my disc conversion also. I have everything removed on the front to re-paint the frame so i am considering replacing while it is removed.

are there any better options if you have rear disc conversion. I have a 1009 and I plan to upgrade the master cylinder for the larger rear reservoir at some point.

Thanks
Rich

 

[Chaski]

They state it is for front disc and rear drum, wonder if it is a problem when you converted the rear to disc.
Mine is currently removed from the truck and looks pretty bad, was considering replacing it.
I assume this is same as stock and since my current one is stock and working with the current rear disc, the new one would work with my disc conversion also. I have everything removed on the front to re-paint the frame so i am considering replacing while it is removed.

are there any better options if you have rear disc conversion. I have a 1009 and I plan to upgrade the master cylinder for the larger rear reservoir at some point.

Thanks
Rich

This is what I did, it is a pretty close swap. I had to redo a couple lines if I recall.


Wilwood 260-11179

 

[Barrman]

Rich, if your factory one is working now, keep it. I was happy to see there are some out there. Which is why I linked it.

I did the manual control proportioning valve on my '67 Cooper S autocross car. It was a pain to get that last little adjustment just right. Then the sun came out or it rained or I changed tires, etc... For racing, I like the manual knob though. For street driving or for a street vehicle other people who don't "feel" things like I do. I want to stay automatic.