Rebuild service for combination/proportioning valve
 

Does anybody on the forum offer rebuild services for 71-72 combination/proportioning valve or know of a service from a vendor? I would be more interested in an original 71-72 combination valve that has been rebuilt than a new square looking brass one that are offered nowadays. I am not opposed to the new brass ones, but I am a little concerned about it being correct for a long bed C-10 with disc in front and drum in back because they are usually listed as suitable for general purpose GM disc/drum setup. I posted a want ad for one here but thinking of sending it out for rebuild if I get somebody offering me one. http://67-72chevytrucks.com/vboard/s...d.php?t=833978

Re: Rebuild service for combination/proportioning valve
 

Illegal for a business to rebuild or tamper with in the State of California.

Re: Rebuild service for combination/proportioning valve
 

Interesting the things they decide to make laws about. It must pay pretty good to be a politician and dream this stuff up... I wonder if they now stop traffic at the border to check and confiscate fresh fruit AND rebuilt proportioning valves coming into the state. :) It's been a while since I drove out there.

Re: Rebuild service for combination/proportioning valve
 

Where are you finding this information? It wouldn't surprise me, but I've never heard of this.

For the OP, here is a link to kits. They really aren't that difficult to do.

https://www.google.com/search?q=71-7...client=gws-wiz

Re: Rebuild service for combination/proportioning valve
 

LOL!! California............Who cares!! LOL!!

Re: Rebuild service for combination/proportioning valve
 

You could always go with an adjustable one if you are worried about the proper loading. I do not know what brand the one is on my 70, but when it was converted to front disk brakes (Stainless Steel Brakes Kit) it was provided with the kit to get the proper balance feel.brake

Re: Rebuild service for combination/proportioning valve
 

Never seen business/company advertise or sell rebuild. Info came from Power Brake Sales Sacramento California.

Re: Rebuild service for combination/proportioning valve
 

Old Auto Restorations https://oldautorestorations.com/ advertise they rebuild them. Gonna give them a shot at mine at some point when I get to it.

Re: Rebuild service for combination/proportioning valve
 

I have a brand new one that leaks from the plastic terminal for the brake light.
It requires rebuilding.
One mile on the truck.
Aggravating

Re: Rebuild service for combination/proportioning valve
 

I used to go to big Corvette shows and there were vendors that bought cores and rebuilt them. Vette Brakes and Products is out of business now. Lonestar calipers might. Maybe Muskegon Brakes? That one is really not all that special, GM disc/drum is used in a bunch of cars and trucks for years. But I know what you mean. The one on my '83 K20 is stuck and I bought an aftermarket one but I can't quite bring myself to install it yet.

Re: Rebuild service for combination/proportioning valve
 

I've gone through 2 myself. Mine leaked from the front button, as well as where you mentioned.

Re: Rebuild service for combination/proportioning valve
 

Found these ads in Hemmings:
James Ament oldautorestorations@gmail.com
Restore your brake proportioning valve back to like-new operating condition, rebuilding valves from the 60's through the early 90's.

White Post Restorations, www.whitepost.com they show proportioning valve rebuilding as one of their services.

Re: Rebuild service for combination/proportioning valve
 

Are you guys talking about new to you cast iron ones that are leaking, or new brass ones?

Re: Rebuild service for combination/proportioning valve
 

OK I'm interested, but I don't see a way to actually choose the correct kit for a 71-72 valve.

Re: Rebuild service for combination/proportioning valve
 

The specs are on one of these pages that Keith Seymour provided awhile back.

Re: Rebuild service for combination/proportioning valve
 

Mine is Brass or at least plated brass. I checked the Summit feedback and the leaking valves seems to be quite prevalent.
I was shopping for a different brand and didn't have much luck as they all seem to be identical.
I attempted to repair the leak. I unscrewed the top fitting where the elect connection goes and replaced the "O" ring. No joy it still leaks. Later I got some help, to pump the brakes, and found the front screw in plug also leaks.

i see where Inlinetube sells the 1971-77 GM Disc Drum Proportioning Valve Lead Wire (Switch Only) for $12. If I thought it would fit the issue I would purchase one. I believe the brass header must have a burr in the hole. Even if it fixed the leak I would still have the other one to deal with so I changed my mind. I included a link to the lead wire switch;
https://www.inlinetube.com/products/...13202138857533
A picture is also included of my installed valved with the leaking areas marked.

Re: Rebuild service for combination/proportioning valve
 

So is it also illegal to replace other brake components like master cylinders, calipers, etc. that aren't OE? I mean, nothing CA lawmaker do would surprise me, but still...

Re: Rebuild service for combination/proportioning valve
 

In my limited research I failed to find the law that addressed this;
Illegal for a business to rebuild or tamper with in the State of California.
If anyone can find a link to the statutes it would be appreciated.

I did find information on how to rebuild the 1978 - 1982 GM 1257208 Combination Valve Rebuild;
https://www.musclecarresearch.com/gm-1257208-rebuild

And the rebuilding kit here;
https://www.musclecarresearch.com/gm-pd-valve-kit-3

Re: Rebuild service for combination/proportioning valve
 

Here in California no one seems to want to fix parts. They just replace them with sometimes faulty remanufactured parts. Unfortunately to make money, good parts are changed as well. My BIL had his OE calipers changed out with some crappy remans some time back. FWI he was told they could not be rebuilt due to state law. Another reason I do everything I can myself.

Re: Rebuild service for combination/proportioning valve
 

:bsf:

Re: Rebuild service for combination/proportioning valve
 

That is a Corvette one so it is 4 wheel discs. Might be the same parts as a disc/drum, but I doubt it.

Re: Rebuild service for combination/proportioning valve
 

I used to rebuild calipers, master and wheels cylinders when I worked as a mechanic. I can't picture even California sorting that deeply into the pile for something to outlaw. I expect that people wanting to just replace the part, even with a reman, are doing it because it is more profitable. We used to send carburetors out for rebuild by a local shop, because they were really good at it, and it would be less cost effective for one of us to do it in-house.

Re: Rebuild service for combination/proportioning valve
 

MARKDTN wrote, "That is a Corvette one so it is 4 wheel discs. Might be the same parts as a disc/drum, but I doubt it."

I believe MARKDTN is correct from the simple fact that the Combination Valve shown does NOT include a Metering Valve on the end for the Front brakes.

Re: Rebuild service for combination/proportioning valve
 

The stock cast iron valves are fine, it's the brass ones that are notorious for leaking from the metering valve. I bought the Wilwood combo valve, but haven't installed it. I'm leaning towards using a rebuilt stock combo valve instead....but I'm still undecided. The metering valve RichardJ shows above is a replacement for the leaky brass valves. Which leads me to ask, does anyone know how to remove the metering valve from a stock Bendix combo valve? I'll be attempting to rebuild my stock valve in the near future.

Re: Rebuild service for combination/proportioning valve
 

That's because there isn't one. Word around the campfire is the brass valves are originally from late 70s/early 80s Camaros. The only real options I see are to rebuild a stock combo valve, or ditch the combo valve all together and install an adjustable proportioning valve.