So my 2003 Yukon with 135,000 miles AC started to whine a little so I knew it was on its way out. it sounded like a power steering pump low on fluid. I decided to fix it now rather than wait for it to totally fail.
I bought a unit from 4 Seasons at Rockauto, price was decent and came in a kit.
After install and initial evacuation and charge the unit had a noticeable growl? Had me scratching my head. I am not an AC expert but have installed and charged 20 or so AC compressors on cars and all worked out fine so far.
The growl got me thinking what it could possibly be. I did install new oil as instructed. I was pretty sure that part is correct and 4 seasons AC parts have been around many years.
After thinking on this I was kicking around the install to see if I made a mistake. The only thing I did that I did not like was the actual installation of the 4 mounting bolts. The bottom bolts are very difficult to access and remove or install. The bottom front bolt has near zero access and took me an hour to remove, a little less to install. Due to the effort involved in removing these bolts I Tightened the lower 2 bolts fully and then went up top and tightened the upper 2 bolts. I know better but the bolts were so hard to get to I went with that plan on install. My Mistake. Un even tightening can put stress on the compressor body that needs to be avoided.
So in an attempt to eliminate the growl in my new AC compressor I loosened the 4 bolts that mount the compressor to the engine block. I only backed them off enough so there was near zero torque clamping the compressor to the engine block. Then I started the engine with it semi loose. It fired up quietly AC on, growl gone. This is great news.
Now I shut it down and started tightening with much more care than the first time. Torqued the top bolts till all slack was gone and the bolts were touching and just starting to clamp the compressor. Now I went underneath and tightened the lower 2 mount bolts till they were just touching and all slack was gone. This time I tightened a little on the bottom and then jumped up top and tightened the two top bolts slightly adding a little torque evenly to both top bolts. Went down underneath and did the same to the bottom 2 bolts.
Did this process 3 more times till all 4 bolts were tight and torque was the same on all 4.
Fired it up again, now torqued evenly the AC Compressor is much quieter. A little louder than I remember the factory pump being but 90% quieter than the first install. I hope my initial torque process did not do permanent damage to the compressor.
I write this and point out my Boo Boo because others may face the same issue. You can't reach all 4 bolts from the top or the bottom so take your time and make sure the 4 mount bolts are brought down evenly so you do not add any internal stress to your brand new AC Compressor.
FYI #2, when your order parts make sure you order parts for an AC system that has rear AC if your truck has rear AC. The Accumulators are not the same Rear Air or No Rear Air. They look the same but the low pressure line mount is rotated 90* to the side with rear air and straight up without. They are not interchangeable.
It is 103 outside and my AC had to be turned down on a short drive as it was getting too Cold inside. So semi success. Wish I was more careful on the first bolt torque and avoided this.
Hope this helps the next guy.
I bought a unit from 4 Seasons at Rockauto, price was decent and came in a kit.
After install and initial evacuation and charge the unit had a noticeable growl? Had me scratching my head. I am not an AC expert but have installed and charged 20 or so AC compressors on cars and all worked out fine so far.
The growl got me thinking what it could possibly be. I did install new oil as instructed. I was pretty sure that part is correct and 4 seasons AC parts have been around many years.
After thinking on this I was kicking around the install to see if I made a mistake. The only thing I did that I did not like was the actual installation of the 4 mounting bolts. The bottom bolts are very difficult to access and remove or install. The bottom front bolt has near zero access and took me an hour to remove, a little less to install. Due to the effort involved in removing these bolts I Tightened the lower 2 bolts fully and then went up top and tightened the upper 2 bolts. I know better but the bolts were so hard to get to I went with that plan on install. My Mistake. Un even tightening can put stress on the compressor body that needs to be avoided.
So in an attempt to eliminate the growl in my new AC compressor I loosened the 4 bolts that mount the compressor to the engine block. I only backed them off enough so there was near zero torque clamping the compressor to the engine block. Then I started the engine with it semi loose. It fired up quietly AC on, growl gone. This is great news.
Now I shut it down and started tightening with much more care than the first time. Torqued the top bolts till all slack was gone and the bolts were touching and just starting to clamp the compressor. Now I went underneath and tightened the lower 2 mount bolts till they were just touching and all slack was gone. This time I tightened a little on the bottom and then jumped up top and tightened the two top bolts slightly adding a little torque evenly to both top bolts. Went down underneath and did the same to the bottom 2 bolts.
Did this process 3 more times till all 4 bolts were tight and torque was the same on all 4.
Fired it up again, now torqued evenly the AC Compressor is much quieter. A little louder than I remember the factory pump being but 90% quieter than the first install. I hope my initial torque process did not do permanent damage to the compressor.
I write this and point out my Boo Boo because others may face the same issue. You can't reach all 4 bolts from the top or the bottom so take your time and make sure the 4 mount bolts are brought down evenly so you do not add any internal stress to your brand new AC Compressor.
FYI #2, when your order parts make sure you order parts for an AC system that has rear AC if your truck has rear AC. The Accumulators are not the same Rear Air or No Rear Air. They look the same but the low pressure line mount is rotated 90* to the side with rear air and straight up without. They are not interchangeable.
It is 103 outside and my AC had to be turned down on a short drive as it was getting too Cold inside. So semi success. Wish I was more careful on the first bolt torque and avoided this.
Hope this helps the next guy.
