HELP!Is the Disc brake hold off valve adjustible?
 

Im just wondering if on a car with the power disc brake option if these are adjustible because the one end with the rubber nipple turns by hand and if so what way do I go to relieve or take away brake pressure and do they come already set when you buy one.It seems my brakes are rubbing some and I changed the master cylinder,rotors, calipers ,wheel bearings and greased pins and distribution block and brake lines.Thanks.Any help would be much appreciated since I want to get this fixed.

I believe the rubber nipple is a protective cap for the valve inside that moves. :)

Pictures?

And you mean hold off valve for the rear drums right?

The problem you are having is one I've seen many times on customer's GTO's when they have an aftermarket brake booster(repro) The problem is that the dimensions of the booster are a little off and you have to put a washer on each booster stud to shim the master
cylinder away from the booster a little. Usually one washer on each stud will do the trick. I
had to do this on my own GTO when I installed a repro booster. There is no adjustment on the auxiliary brake valve.

What about the threaded rod that goes through the firewall from booster to master cylinder.I thought thats what they adjusted and came preset from them when you bought a brake booster?Also how thick of a washer did you use?Thanks

Hey GTOHURSTJUDGE.That did the trick with the 2 washers.I want to thank you so much.I had replaced 3 master cylinders,calipers,rotors,pads,bearings,brake lines,distribution block,proprotioning valve,rear wheel cylinders to no avail.I guess it needed new everthing anyways>the brake booster I replaced a few years ago to get one that looked new and plated so it was the culprit

Car now rolls back on the slightest incline when clutch is in which it didnt before and brakes feel like they did years ago and not so stiff brake pedal pressure

Nice call gtohurstjudge!

I'm glad I could help.....as I said I've run into this every time I've installed a repro booster. This problem has been around for ten years.....I'm amazed they haven't done anything to solve the problem yet. The rods they give you aren't adjustable so you have to shim the master cylinder to get the proper clearance. If you wanted to you could shorten the
rod with a grinder and get the same result.

Thanks for the tip, gtohurstjudge !