[GLAmes]

My car has a factory vacuum brake booster that was recently repaired by White Post Restorations under warranty because it leaked. Great service, no complaints. Yesterday, while checking for a power steering leak the brake lights lit up. I hadn't applied the brake pedal. My immediate suspicion went to the booster but even after I shut off the engine the lights stayed lit. I cracked the bleeder screw and the lights went off. Today I disconnected the vacuum hose and hooked up a gauge. 18 inches at an idle, drops to 15 or 16 when the engine revs and jumps to about 22 when the throttle is released, then back to 18. That seems OK to me. Here is the weird part. With the vacuum hose disconnected during my check the brake lights came on. I jacked one front wheel off the ground and the brakes were, in fact, applied. I waited a few minutes and they went out. I reached into the window and started the engine again without touching anything except the key. In a couple minutes the brake lights illuminated again. Anyone care to take a crack at what would cause the brakes to build pressure while the engine is idling with the vacuum hose disconnected?