I am trying to chase down what appears to be a vacuum leak. When I am in drive with my torque-flite auto at a stop and hold the brakes down (power brakes, disc-drum on my AAR) the engine slows way down below 500 rpm (even on fast idle at above 1000 rpm set) and will die if left for a few minutes. I am wondering if the check valve on the power brake booster could be the problem. Any thoughts on that? Thanks.
