Alright, so last weekend I put about 150 miles on the Volvo and she ran ok for her age. Go to start her today and she idles ok until I apply the brake. When I do she struggles hard to run and will stall unless I let up off the brake pedal. I can also hear what sounds like air leaking when I apply the brake, from under the dash it seems. I checked my vacuum lines with a propane torch and no change in idle so I'm not sure exactly what the issue is. Could I have a faulty brake booster?