The Serpentine belt on my truck shredded while I was driving. I went and bought a new belt and put it on and less than 10 miles later it shredded again. I took it to a local shop and they said I have a bad idle pulley, bad power steering pump pulley, and the pulley on my a/c compressor is bad. They suggested I replace the entire a/c compressor which ended up costing around 600 dollars. Prior to taking my truck there the a/c worked and blew cold out of the defrost vents but it has never blown out of the front vent . Which leads me to believe I have a vacuum leak because the compressor didn't fix how cold or how much air blew through the vents. My question is did they need to replace the whole compressor if it was just a pulley issue and not an a/c issue?
My car has 140000 miles.
My car has a manual transmission.
Sometimes when the pulley goes bad on the A/C compressor this means the pulley bearing went bad. When this happens, sometimes the bearing seizes and spins on the front of the compressor area where the bearing sits. This will cause damage to the front of the compressor and require replacement. The A/C uses a vacuum system on the vent doors and you should check the vacuum system for leaks near the evaporator case in the engine compartment on the passenger side rear. The system has a small canister that stores vacuum for A/C use. Like you said, you should have a technician look for breaks in the vacuum lines. It would be hard to confirm the issue without looking at this in person. If you want to have this checked out, a technician from YourMechanic can come to your car’s location to diagnose the issue and make the correct repairs.