OK guys after more than 30 years of working on cars I just replaced my first compressor and serviced up an a/c system for the first time. I have a 96' F150 5.8l with 78k miles on it. The compressor was cycling off and on and when I checked the low side the pressure was bouncing back and forth between 25psi and about 15psi which I'm assuming was kicking the low pressure switch causing the cycling? I added a can of freon and went looking for a leak. I noticed the tale-tale oil line across the inside of the hood and discovered that the old compressor was leaking out the shaft. I bought a new compressor with clutch, installed it, pulled a vacuum for about 1.5 hours and then recharged it with the 2lb 6oz of R134 as specified on the sticker under the hood. When I started it up I was getting 45psi on the low side and almost 275psi on the high side and saw little if any movement of the needles. Inside vent temps were about 52 degrees. I thought something isn't quite right here. After reading through many of the posts on the forum I went out and checked and noticed that I wasn't hearing the fan clutch engage. The fan seemed to always be freewheeling. I went down today and bought a Hayden severe duty fan clutch and installed it. Today it's 87 degrees and I now see 33psi on the low side and about 225psi on the high side and vent temps at 1200rpm (parked) are about 44 degrees and I'm now hearing the fan clutch engage and disengage the fan. On the road vent temps get down to about 36 degrees.

Does this all sound about right? I'm also curious as to whether you think the bad fan clutch was causing high pressure which is what caused the old compressor seal to fail?

 

You Hit The Nail On The Head! Looks To Me You Did Everything Right.the Fan Clutch Is One Item That People Miss A Lot Of The Time,good Observation,looks Like You Have Your Problem Solved.

 

yup. 33 is a tad low, but nothing to worry about. if you have 44 parked and 36 running, that is good temps. you pretty much did everything by the book.