Fellow Volvo Owners,

It has been a minute since I have been able to post on this site. I recently replaced all my vaccum lines in the car to include the lines inside the cabin, due to deterioration, cracking, tears, etc. It has resolved most of my vaccum leak problems. I had a surging idle problem that appears to be taken car of after I replaced the vac line,had the injectors ultrasonic cleaned by Mr. Injector in Idaho (great work by the way), and cleaned the throttle body. I started the car today and it fired up strong, but it appears that I have a hissing sound coming from the small hose that attaches to the brake in-line check valve (black and white plastic valve) and the intake manifold. At this point, I am not sure if it is the valve or the hose, but I replaced the hose already and ensured the connections were tight. I have no brakes (partly due to a leaking junction block), but when I do press the brake the engine's idle lowers almost to the point of stalling. Is it possible that check valve is faulty and needs replacement or is there something else going here? I welcome the experience of you fellow Brick owners and hope you can lead me in the right direction. Is there a way to test this valve? Thanks.

Kyle