Originally Posted by dirtyharry

I think the wheezing your describing is the vacuum pump at the front of the 617, its normal to hear a sound from it whenever you pump the brakes(engine off)?? i think as its trying to draw from the pump. It is possible for the rear seal on the master to leak into the booster as well, if you unbolt it you may find brake fluid in there. it could be that the previous owner never followed procedure as far as bleeding the master/ he destroyed the rubber on the pistons by stroking too much while bleeding. taking any of the lines off will not free up air, but bleeding it back into the cylinder will. or as Frank suggested cracking the lines.