So it appears this valve is in need of replacement and was wondering if anyone has deleted it, and used an adjustable proportioning valve for the rear brakes? Scott
The hold off valve limits pressure to the front brakes until a certain pressure is reached in the rear brakes. It is used with front disc brakes because the disc brake pads are always in contact with the rotor, and they apply more or less instantaneously, while the rear brakes have clearance with the drum, and spring tension to overcome. Later cars used combination valves which combine the hold off valve, proportioning valve, and warning light function. The 1970 and earlier separated the valves. If you wanted to eliminate the separate hold off valve, you could just use a 71-72 combination valve. Not sure how easy or difficult that would be, never looked at doing it. I know www.ss396.com has the Chevy separate hold off valve in their catalog. Here's one on E Bay. http://www.ebay.com/itm/1970-CHEVEL...r_Truck_Parts_Accessories&hash=item5af068731d
