I thought my A/c was not working but moved the selector switch and felt cold air out the defroster vent. I don’t hear any hissing inside the car at all. I do hear hissing when I brake but the brakes feel fine and only hear the hiss while coming to a stop. Once stopped I don’t hear anything, I figure this must be related? Any suggestions?

Jim
starbuck@gate.net

 

Start the car for a couple of seconds. Then turn off the engine. Wait a minute or 2. Then press the Brake pedal. You should have power assist for at least 2-3 pedal strokes. If not, check your vacuum check valve on your power booster. Defrost is usually default mode if your hvac controls aren't working. Take your dash panels off to take a look at the hvac controls. If it works on vacuum, there should be vacuum at the hose that goes to the blend door when in the vent position. If electric, make sure the motor is moving the blend door. If not test for power at the motor and the contoller.