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South Georgia | Our 4055 air conditioner went to acting up this summer. I don't know what the original symptoms were, I was completely unassociated with this project then. A local mechanic put a compressor clutch on it. That didn't fix it, so it was sent to the Deere dealership. They put a new compressor on it and sent it home. Hired guy complained, so I went to look at it. (This is where I came into this project, I hadn't laid eyes on it before this point.) After tightening some fittings and putting 3 cans of freon in it, he said it was a little better, but not right. When it got back to the shop, the vent temp was over 80 degrees. (I don't remember what, exactly, that's been a month or more ago.) Sooo... I opened the roof of the cab, and immediately saw a big part of the problem. All the weatherstripping/insulation around the evaporator was gone, including the stuff that stops up the big hole on the left side of the evaporator that the high and low pressure lines go through. If the air doesn't have to go through the evaporator, it danged sure isn't going to be cool. I fixed all that, and had the vent temp around 70, which was a vast improvement, so I let it go.
Nobody has complained or even mentioned it to me since.
Today I got in it to move a piece of equipment, and while it was better than not having it, it wasn't that much better than not having it. Vent temp was about 82, regardless of rpm. At idle, the low pressure side was at 40, and the high was just below 200. Increasing engine RPM decreased the low pressure side, but didn't have much effect on the high pressure side. Increased rpms got the low pressure side down to around 15, with the high side still near 200. As the tractor has the fan clutch lock up 'kit,' I'm pretty sure it has adequate airflow through the radiator, but to make sure the condenser had enough 'cooling,' I ran water over it. I got the high side down to... I think 140-150ish this way, but the vent temp didn't really change.
Maybe the heater valve is cracked open... Well, I tried it, but it was stuck. The dealership had one in town, so I went and picked it up. Installed it, and got the vent temp down to around 72. Of course, by this time the sun had moved, and the tractor was in the shade (about 6:45 or 7:00 local time), and the ambient temperature had started to fall a little, too, so the heater valve may be a fluke. While I was in the top of the cab, I checked the evaporator temperature. It was around 45, which I thought was a little high, but what do I know, I'm not an air-conditioner man.
The cab drains are not plugged, but in 30 or 40 minutes of sitting in one spot running, they only dripped a very little bit of water. To compare, I cranked my truck, and left it idling next to it, and in five minutes, it had a big danged puddle. Also, the low pressure line going to the suction side of the compressor is barely cool to the touch, and isn't sweating. The high pressure line is hot, but the low pressure line isn't cool. I have an infrared thermometer, but I didn't think to check the line temperatures.
Before anybody asks, no, the professional mechanics that had first shot at it didn't bother to replace the dryer or the expansion valve.
Any help? I gotta tell ya, 72 degree vent temps don't really hack it in South Georgia.
Adrian | |
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4055 A/C problems...
