The proportioning valve has a button on the front of it. You need to hold the button in to bleed the rear brake. I believe it is for safety incase one of the lines break all the fluid wont leak out Bill ----- Original Message ----- From: Larry Hickman To: Chevelle List Sent: Wednesday, March 12, 2008 4:17 PM Subject: [Chevelle-list] Proportioning Valve Problems
Hey Guys I did a front power disk brake conversion on my '71 Chevelle. Everything fit together very well and looks as it should. My problem is I can't bleed the rear brakes. I can crack the brake lines ahead of the wheel cylinders, and get fluid when the pedal is pumped, but can not get any air or fluid out of the bleeders on either rear wheel cylinder. I have completely removed the bleeder valves to look for an obstruction of some sort, and they are clear. The visible portion of the needle valve on the proportioning valve block does extend slightly when the brakes are activated, but it only moves about a 1/16th of an inch. Is this the way they are supposed to work ? The kit came with a new proportioning valve for front disk/rear drum brakes that is supposed to be correct for all GM "A" bodies of this era. I suspect this to be the problem, but don't know how to test it. Any ideas ? I am stumped. ------------------------------------------------------------------------------ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.