Cab not cooling well with A/C

[cnowalk]

I have a 1998 ECSB and since I’ve had the truck, the cab has never cooled well when running the A/C. I would have to drive around with it on full blast to stay cool, and even then I’d still be sweaty. Even despite the air coming from the vents feeling nice and cold. Installing a new blower motor helped a little, however cleaning the evaporator coil did not.

While replacing the LIM gasket back in December, I damaged the A/C line going to the compressor and finally got around putting in a new one this weekend. I then evacuated and recharged the system. I pulled vacuum for an hour and then it held vacuum for over an hour. Oddly, I couldn’t quite get the pressures right during recharge, particularly on the low side. Air coming out of the vents gets down to around 46° which is fine, and when cruising, it hovers between 50-52°, also fine (I think). I still have the same issue as before, and it may even be worse as the compressor will kick off and stay off long enough for the air to warm up. Based on the condition of the orifice tube, I’m probably better off replacing more then just A/C lines. I live in Florida so I’d really like to get it working right.

 

[df2x4]

My Suburban behaves in a similar way. It cools, but not nearly as well as my red truck. I've replaced most of the lines and the blower motor for different issues in the past. Condenser and everything has been cleaned well. My mechanic seems to think that my issue is the compressor. He says there's internal wear which is causing a loss of efficiency. I've been just dealing with it. I plan on running it until it dies completely, then it'll get replaced.

EDIT - There was crap in my orifice tube both times my mechanic has taken it out to check it, which seems to strengthen his guess about the compressor. At least IMO, I know very little about these systems.

 

[cnowalk]

My Suburban behaves in a similar way. It cools, but not nearly as well as my red truck. I've replaced most of the lines and the blower motor for different issues in the past. Condenser and everything has been cleaned well. My mechanic seems to think that my issue is the compressor. He says there's internal wear which is causing a loss of efficiency. I've been just dealing with it. I plan on running it until it dies completely, then it'll get replaced.

EDIT - There was crap in my orifice tube both times my mechanic has taken it out to check it, which seems to strengthen his guess about the compressor. At least IMO, I know very little about these systems.

I’m thinking I’m in a similar boat. I know that crap in the orifice tube is not helping anything nor is it a great sign. I’m just not sure if it’s old debris or if my compressor is also on it’s way out. And there’s probably more crap in my system than what I saw last night. At least if I replace everything I know it will be clean, and I’d get to use my new tools again!

 

[df2x4]

I’m thinking I’m in a similar boat. I know that crap in the orifice tube is not helping anything nor is it a great sign. I’m just not sure if it’s old debris or if my compressor is also on it’s way out. And there’s probably more crap in my system than what I saw last night. At least if I replace everything I know it will be clean, and I’d get to use my new tools again!

If you end up replacing everything let us know how it turns out! I'm curious to see if a new compressor fixes the issue, but it seems like a good idea to replace everything else at the same time considering the debris in the tube.

 

[Eveready]

I too am interested in your results. Mine is working "OK" but could probably be better and when it gets hot in near coastal NC it gets REALLY hot. Re the lines, unless they are corroded it seems to be that 100 pounds of compressed air would blow them out pretty well assuming you could open at both ends. My guess is the elderly compressor is likely the culprit.

 

[biggbiker]

I have 2 GMC400s , a 96 C1500 and a 99 Yukon. The 96 has 222k miles, when I bought it in 2013 it was mediokre A/C at best. It was losing refrigerent. I replaced the orafice, line, compressor, condensor and dryer. works great. The 99 has 57k miles worked great when I bought it in 2015. Stoped working , I noticed the compressor was leaking. So I replaced compressor, orafice, dryer/ accumulater, condenser and rear expansion valve (has rear A/C). Works fantastic! My research is they wont warrenty a compressor without a condensor change if there is debris in the orafice. Cost about $ 700 each vehicle to fix, having a friend ( half price labor) do the work, or about $300 parts. A small price to pay for such comfort. That is 1 new truck payment in my book. I bought these trucks knowing money would need to be spent every so often to keep everything working as it should.

 

[cnowalk]

Sounds like I’ll be replacing more parts, as expected. I’ll definitely update this thread once I do! I’m hoping for good results and I would imagine after a new compressor, condenser, receiver/drier, and flushing the evaporator core and lines that it should help out a lot.

 

[Eveready]

I have 2 GMC400s , a 96 C1500 and a 99 Yukon. The 96 has 222k miles, when I bought it in 2013 it was mediokre A/C at best. It was losing refrigerent. I replaced the orafice, line, compressor, condensor and dryer. works great. The 99 has 57k miles worked great when I bought it in 2015. Stoped working , I noticed the compressor was leaking. So I replaced compressor, orafice, dryer/ accumulater, condenser and rear expansion valve (has rear A/C). Works fantastic! My research is they wont warrenty a compressor without a condensor change if there is debris in the orafice. Cost about $ 700 each vehicle to fix, having a friend ( half price labor) do the work, or about $300 parts. A small price to pay for such comfort. That is 1 new truck payment in my book. I bought these trucks knowing money would need to be spent every so often to keep everything working as it should.

You make an excellent point. The conventional wisdom is that if you spend two payments a year on maintenance a vehicle will run forever. If you extend that to two "modern" payments a year one of our older trucks will last a long time. I defer to your expertise re ending an AC problem for a long time. Good stuff there!

Does anyone have favorite source of AC parts? Since parts quality seems to vary all over the place it would be good to know a reliable source.

 

[cnowalk]

You make an excellent point. The conventional wisdom is that if you spend two payments a year on maintenance a vehicle will run forever. If you extend that to two "modern" payments a year one of our older trucks will last a long time. I defer to your expertise re ending an AC problem for a long time. Good stuff there!

Does anyone have favorite source of AC parts? Since parts quality seems to vary all over the place it would be good to know a reliable source.

I was going to go with a certain discount auto parts website, but I also would like to know if what I’m buying is quality. It would be nice to make this repair once and be done.

 

[Oldblue98]

I was going to go with a certain discount auto parts website, but I also would like to know if what I’m buying is quality. It would be nice to make this repair once and be done.

Is your blend doors doing there thing correctly ? You sure you are not getting a hot & cold mixture situation ? Maybe cold out the top vent and hot or warm out the bottom ? Just a thought.