I am in process of rebuilding a 67 RS Convertible and just now discovered a leak from the rear cover boot on the orginal (?) proportioning valve. This ride has had the front disc brake conversion (I think they are from a 69 or later with the single piston caliper) and standard drums in the rear. Do I just replace the unit ($195) OR would I be better off using my adjustable proportioning valve with its 0 to 3000 psi gage attached? It looks to me the original valve is controlling the front discs is this correct or should the porportioning valve control the rears? How would I adjust the valve with the gage attached?

Ken

The original valve by the master cylinder is a metering (aka holdoff) valve, not a proportioning valve.

See the spirited discussion in this thread...

http://www.camaros.net/forums/showthread.php?t=30947&highlight=holdoff+valve

Do not use an adjustable prop valve for the front brakes. You're better off just eliminating the front brake valve altogether than doing that.

The original valve by the master cylinder is a metering (aka holdoff) valve, not a proportioning valve.

See the spirited discussion in this thread...

http://www.camaros.net/forums/showthread.php?t=30947&highlight=holdoff+valve

I think you are speaking about the brake splitter block (low pressure switch which mounts beneath master cylinder, the pro valve is mounted to the power booster with a nut on the left side.
Ken

If the valve has all the brake lines running into and out of it it's a combo valve from a later model car, common in conversions. You can either replace it with new, or bypass it and run an adjustable proportioning valve in the rear line only. I'd remove any pressure gage, it won't tell you anything unless you have one in both front and rear lines, and you adjust the brakes by feel anyway, not the gage. The gage is a possible leak or failure source and should not be used unless it has a definite purpose to serve, - in my opinion.

If it's a separate roundish valve with big nut and is above the brake light switch/splitter, then it's a hold off valve for the front brakes. You can remove this valve with no problems or adjustments. I have a full explanation of this valve on my web page below.

I'm in Salinas too, we'll have to meet some time.
David

You sound like the "MAN", yes let's get together sometime. Thanks for the input I will PM you with some more questions. I think you will like the ride I am putting together!
Ken

New seal kits are available through Heartbeat City. I fitted a kit due to the same rear leak and..:thumbsup: