my buddy bought a 97 4.6 F-150 today with 128,000 on it. Runs perfect however the air compressor is making a really bad knocking sound when the air is off. A mechanic friend told me the compressor was bad. Does anyone have instructions/pictures of how we could go about replacing this ourselves? Thanks!

email is bigpat_98@hotmail.com

 

If it is making noise with the A/C off, then the you will need to replace the coil, pulley, and disc.

 

Yopu should be able to replace the clutch Assy. without having to worry about recharging the A/C system. If it makes noise with the A/C off then I would also suggest that it is the clutch and not the compressor.