Help, I need a 71&up brake proportioning valve

**njsteve** · #1 10-29-2010, 01:39 AM

Anyone have the cast iron disc brake proportioning/combination valve for a 71 and up Camaro/Firebird with disc/drum? I believe the other GM models of the same era use this same valve. The current replacement seems to be a brass valve that looks nothing like the original.

I just noticed that mine is seeping fluid from the red arrow location. Luckily I use silicone brake fluid so no paint is damaged, but it is pissing me off, as well as being a major safety issue.

I dont see anyone selling these anywhere. You can find them for the Ist Gen F-bodies but not the 2nd gens.

fro71 · #2 10-29-2010, 06:03 AM

inline tube has them http://www.inlinetube.com/ was just looking at them the other nigh.

chris

**njsteve** · #3 10-29-2010, 03:27 PM

They don't sell the original cast iron valve, just a brass replacement that looks nothing like the original part.

Keith Tedford · #4 10-30-2010, 04:53 AM

I was talking to John Stuart Power Brakes in Stoney Creek, Ontario and they said that they can rebuild these 1-905-662-7274. I'll be sending them one of these cast iron units that I took off of our '72 Lemans Sport along with a load of other stuff. I replaced it with the brass one that GM was selling at the time. You might want to check with them to be sure.

L78steve · #5 11-10-2010, 04:40 AM

If you still need one I have one from a 74 Z/28 and my have one from a 71 Nova.

**njsteve** · #6 11-12-2010, 01:57 AM

Thanks for the offer, but I got an extra on its way and also sent mine out to be rebuilt. [img]<<GRAEMLIN_URL>>/beers.gif[/img]

**njsteve** · #7 11-12-2010, 01:58 AM

Got the proportioning/combination valve back from a Performance Years website member, 70RAIII (Bill Oxley) who did a really nice job rebuilding it. He indicated that it was all stuck inside, so it wasn't really functioning as anything other than a T-fitting between the front and back fluid routes. Now it's actually working as designed, which is a good thing since if I recall correctly, one of the critical roles of this valve is to internally shift and block the internal passages if one circuit springs a leak and loses fluid. That way you still have braking power for the remaining circuit.

Another thing I noticed is that the purple DOT 5 silicone brake fluid turns yellow after a few years. I'd imagine that means it's time to replace it all, which I did. I flushed the entire system and replaced it with new DOT 5 silicone brake fluid, about four bottles worth, to get all the old stuff out and completely flush the system of the four year old fluid.

The newly refurbished proportioning/combination valve, just back from Bill Oxley:

And after the installation and the brake bleed-a-thon:

**SuperNovaSS** · #8 11-12-2010, 02:32 AM

Steve,

Out of curiousity, is there a reason you did not try to tackle the rebuild yourself?

Jason

**njsteve** · #9 11-12-2010, 03:32 AM

Access to the correct seals/o-rings mainly. No one really sells them anywhere. Not just your everyday standard rubber pieces. Plus, the guy that did my valve does a lot of these contraptions and had the extra parts needed in case something broke, or was too pitted or rusty, which is a rather common discovery when taking them apart.

**SuperNovaSS** · #10 11-12-2010, 03:38 AM

Gotcha, I thought that may be the case.

Jason