n8in8or
I never met a project I didn’t like
This doesn’t seem like the best spot for this thread, but I don’t see a better. Plus this one gets higher traffic so selfishly I’ll roll with it…
For 2 weeks now I’ve been trying to get the AC on my 94 K3500 extended cab working. Over the winter I put all new AC components in it. Hoses, condenser, evaporator, compressor, orifice tube, everything. The compressor was a 4 Seasons R4 new compressor. 2 weeks ago I was ready to charge the AC finally. I started putting a can of R134 in it and before I could finish that can the clutch and/or drive belt were slipping because the high side pressure got so high. It was high 80s outside that day. The engine was at idle, I had the windows open, fan on high and the recirc door open. I ended up smoking that compressor - it would still turn, but not very freely. Later I found some black junk under the pressure switch. I figured I had slugged the compressor.
So I ordered another new compressor, this time a new R4 UAC compressor. I flushed the hoses as well as back-flushed the evaporator through the line at the condenser (I didn’t remove that line from the evaporator because it’s hard to reach that fitting and it’s just an aluminum tube so i didn’t see a ton of benefit removing it. I flushed 1 quart of flush through the evaporator and .5 quart through each of the manifold hoses. I also ordered a new condenser from Rock Auto, but when it arrived it wasn’t the one I wanted - it was the thin core, so I used my low mile one from the Tahoe that already had a variable orifice valve in it. I attempted to charge it again a week after the first attempt. I went through the same process as before, but tried to be more aware since I had a problem once already. Not even a full can in and I’m having excessive high side pressures again!! This time I shut it down before killing the compressor (I think). Well damn!! My only thought was the VOV must have been stuck from sitting dormant for a couple years.
So here we go again. I overnight a new condenser from Autozone so I can get back to working sooner. However after a couple hours of reflection I decide to get a new compressor as well, just to be sure things are fresh. I decide to order a scroll-style R4 compressor by GPD. I heard they’re less capable at low rpm than a true R4 so I ordered an oversized one for a Sub with rear AC. This time I flushed the hoses manually with alcohol until they ran clear and then flushed them 2 more times. I back-flushed the evap and lower line with 2 quarts of flush. I took out the orifice tube that came in the condenser and swapped it for the one that came in the GPD compressor kit just so I knew what it was…..good thing I did! The one in the condenser didn’t have an o-ring on it! I just got it all together and once again I have crazy high pressures, not even 1 can in!!
To recap: 3 different compressors, 3 different orifice tubes and 3 different condensers and still stupid high pressures on the high side. The only thing I haven’t changed is the evaporator, which is the only thing that seems possible though I don’t know why it would be when I was able to flush through it. Oh, when I took it apart last time, I inspected the condenser to confirm it was the problem - there was a ton of oil sitting on top of the orifice tube. I pulled the tube out and tried blowing air through the condenser - it wouldn’t go through and when I removed the pressure oil would puke out at me.
It’s been months since I did the first install, but I believe what I did for oil was put 3 ounces of PAG 150 in the compressor and then put the rest of the 8 ounces in the accumulator based on the information in the service manual.
The second time, the compressor had a sticker specifically saying to put 7oz in the compressor, so I did that and out 1oz in the accumulator, also PAG 150.
This last time it said to put about 60% in the compressor, so I did around 5 oz in the compressor and 3oz in the accumulator. This compressor said to use PAG 46, so that’s what I used.
What’s going on?? Do I have a fluke evaporator?
Here are the gauges with it running today. This is with only 5.6oz of R134. It’s 88 degrees out and 40% humidity.
I REALLY appreciate any assistance! We have a camping reservation 6/18 and if AC isn’t running it won’t be good…..
Thanks in advance.
For 2 weeks now I’ve been trying to get the AC on my 94 K3500 extended cab working. Over the winter I put all new AC components in it. Hoses, condenser, evaporator, compressor, orifice tube, everything. The compressor was a 4 Seasons R4 new compressor. 2 weeks ago I was ready to charge the AC finally. I started putting a can of R134 in it and before I could finish that can the clutch and/or drive belt were slipping because the high side pressure got so high. It was high 80s outside that day. The engine was at idle, I had the windows open, fan on high and the recirc door open. I ended up smoking that compressor - it would still turn, but not very freely. Later I found some black junk under the pressure switch. I figured I had slugged the compressor.
So I ordered another new compressor, this time a new R4 UAC compressor. I flushed the hoses as well as back-flushed the evaporator through the line at the condenser (I didn’t remove that line from the evaporator because it’s hard to reach that fitting and it’s just an aluminum tube so i didn’t see a ton of benefit removing it. I flushed 1 quart of flush through the evaporator and .5 quart through each of the manifold hoses. I also ordered a new condenser from Rock Auto, but when it arrived it wasn’t the one I wanted - it was the thin core, so I used my low mile one from the Tahoe that already had a variable orifice valve in it. I attempted to charge it again a week after the first attempt. I went through the same process as before, but tried to be more aware since I had a problem once already. Not even a full can in and I’m having excessive high side pressures again!! This time I shut it down before killing the compressor (I think). Well damn!! My only thought was the VOV must have been stuck from sitting dormant for a couple years.
So here we go again. I overnight a new condenser from Autozone so I can get back to working sooner. However after a couple hours of reflection I decide to get a new compressor as well, just to be sure things are fresh. I decide to order a scroll-style R4 compressor by GPD. I heard they’re less capable at low rpm than a true R4 so I ordered an oversized one for a Sub with rear AC. This time I flushed the hoses manually with alcohol until they ran clear and then flushed them 2 more times. I back-flushed the evap and lower line with 2 quarts of flush. I took out the orifice tube that came in the condenser and swapped it for the one that came in the GPD compressor kit just so I knew what it was…..good thing I did! The one in the condenser didn’t have an o-ring on it! I just got it all together and once again I have crazy high pressures, not even 1 can in!!
To recap: 3 different compressors, 3 different orifice tubes and 3 different condensers and still stupid high pressures on the high side. The only thing I haven’t changed is the evaporator, which is the only thing that seems possible though I don’t know why it would be when I was able to flush through it. Oh, when I took it apart last time, I inspected the condenser to confirm it was the problem - there was a ton of oil sitting on top of the orifice tube. I pulled the tube out and tried blowing air through the condenser - it wouldn’t go through and when I removed the pressure oil would puke out at me.
It’s been months since I did the first install, but I believe what I did for oil was put 3 ounces of PAG 150 in the compressor and then put the rest of the 8 ounces in the accumulator based on the information in the service manual.
The second time, the compressor had a sticker specifically saying to put 7oz in the compressor, so I did that and out 1oz in the accumulator, also PAG 150.
This last time it said to put about 60% in the compressor, so I did around 5 oz in the compressor and 3oz in the accumulator. This compressor said to use PAG 46, so that’s what I used.
What’s going on?? Do I have a fluke evaporator?
Here are the gauges with it running today. This is with only 5.6oz of R134. It’s 88 degrees out and 40% humidity.
I REALLY appreciate any assistance! We have a camping reservation 6/18 and if AC isn’t running it won’t be good…..
Thanks in advance.
