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Adrian |
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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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| farmerboy50 |
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West Texas | I'm sure you did this but did you clean the evaporator? Also the filter in the top of the cab? Might have a touch too much freon or maybe the expansion valve could be the problem. | ||
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| Adrian |
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South Georgia | No, I don't know why, but doofus didn't think of that while I was in there. I don't think that the evaporator is the problem, though, as I've got lots of airflow out of the vents. The filters aren't the problem, as the fresh air filter is new, and the recirculation filter is clean. What pressures should I have? I was thinking that the high side being around 200 was about right. Is that too high? I wondered about the expansion valve, as I thought anytime you replaced the compressor, it was S.O.P. to replace the dryer and expansion valve also, inasmuch as you've already spent a pile of money on labor, freon, and the compressor, so why not go ahead and do the lower-cost items while the system is open? Thanks for the suggestions, Adrian | ||
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| farmerboy50 |
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West Texas | I would check the evaporator for dirt if you seals were junk. On the 55's and 60's we made it a point to take cover off and clean them. Sure sounds to me like they may be your problem, seen the exact symptoms with dirty evaporator. If condenser wasn't able to pull enough air high pressure would shoot up kicking compressor out. Pull the cover off, if its clean I'm voting expansion valve. Did they change your dryer when new compressor was installed. My opinion on changing clutches, you might as well be burning a 100 bill. | ||
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| johnypop |
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ND | Did your dealer flush the system or just slap on a new compressor? Look at your bill and see what they all did. If it was me I would have replaced the expansion valve and pulled of the cab corner cover and looked at the return lines. | ||
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| KelB |
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Ayr Queensland Australia 4807 | While the pressures seem good it would be interesting to see what the static pressure is. And what the system pressures are when it has run for an hour or so. As another post has asked did the dealer flush the system before instlling the new compressor too much oil in the system will cause poor cooling . You have addressed other items like the heater valve . Somthing we have done here is when we lift the roof is put some sort of insulation on the square cover before putting the roof down . Also as mentioned the TX valve could be stuck in one place when the system is running you should see the low and hight side gauge go up and down. example open the door of the cab i think you would see the low side go higher due to leting more flow I would change out the tx valve going on what you have said and if the dealer has already check to see if it correct one Also slide your condensor /cooler out and hose it out do not just look at it from out side and say its clean look though it. Water is better for this than air .The pressures do not indicate its dirty but clean it anyway . one thing i forgot check the quick couplers under the cabin Edited by KelB 9/10/2010 21:46 | ||
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| MMiller |
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SW Iowa | High pressure is dependant on ambient them and humidity. The hotter more humid the day, the higher the high pressure is. What is low pressure at say 1800-2000 rpms? As long as its over 12 psi or so, it would indicate to me that there is enough freon in it. If the high pressure was very high(think nearing 300 psi) then that would indicate a condensor problem. That is not the case though. I wonder if the expansion valve is not doing its job, as you don't have much temp change at the evaporator it sounds like. Whatever you do, if you open the system again, change the dryer, it should have been changed with the compressor. Its been a long time since I worked on a 55 series Deere, but I usually shoot for 35* evaporator temps with the engine at 1800 rpms. This way I know the a/c will work when the tractor is at WOT working all day in the field. Michael | ||
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| Adrian |
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South Georgia | Nope, no new dryer or expansion valve. I'm going out of town tomorrow, and I don't know if I'll have time to get this done next week before we start picking peanuts, but if I've got time, I might just change the dryer and expansion valve and recharge the system myself. That'll be cheaper than hiring another professional. I kinda agree about the clutch-changing. I don't know what the symptoms were at that point, but as far as I know, all the professional repairs done thus far were unnecessary. Maybe they weren't, but inasmuch as they didn't fix the problem, they at least weren't the whole problem. Adrian Edited to add: I had the top apart today, and while I didn't pay any attention to the downstream side of the evaporator, it didn't appear to be packed full of dirt and mud. Edited by Adrian 9/10/2010 21:48 | ||
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| Adrian |
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South Georgia | Hey, Kel, I don't remember what the static pressures were, but they agreed with the Fahrenheit temperature scale on my set of gauges. Ambient temperature today was around 95 when I started working on it. I didn't let it run for a full hour, but I did let it run a half an hour or longer, and the pressures really didn't change from where they started when I first cranked the engine. TX valve...? You mean the expansion valve? The pressures never fluctuated without me changing something, i.e. increasing the engine speed. After I changed the engine speed and waited a little while (half a minute or so?), they were at a new equilibrium, and again didn't change. To tell you the truth, that's what I'm thinking. I'm not an a/c guru by any means, but I just flat don't understand not changing it and the dryer while the whole system was open. The condenser is going to get cleaned well before we start peanut harvest, but I tried spraying water through it just to make sure it wasn't the problem, with the single result of lower high-side pressures, and no noticeable change in cooling. I can certainly see the benefit in my climate of having some added insulation between the roof and the top of the evaporator cover, I may do that next time I'm in there. On a side note, I emailed Tommy Martin in Pelham a link to your tricycle 4250 pictures from the other day. I haven't talked to him to see what he thought, or if he shared them with the rest of the guys at the dealership, but I thought he'd get a kick out of them. I told Andy about it, and he's pretty sure he's got a customer that would want one if he saw yours. LOL. Thanks, Adrian Edited by Adrian 9/10/2010 22:04 | ||
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| yallardeere |
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| First off, It would have gone to Deere, If you paid them to fix it and it was not done, then they are at fault..Most places will not warranty a compressor without flushing and replacing the drier.... | |||
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| JDTECH |
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NEMO | Expansion valve. Replace the reciever-drier while you have the system down. It should have been done when the compressor was replaced. Deere's warranty on compressors is 1 yr if the drier is replaced and the system is flushed. I think it also states that replacement of the expansion valve is required for the 1 yr warranty. If only the compressor is replaced, then it is only a 90 day warranty. Good luck. | ||
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| milofarmer1 |
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Texas/New Mexico Stateline | You said: "tightened some fittings and added 3 cans of freon." Was the system completely drained at that point? If it was you should have pulled a good vacuum before adding refrigerant. With somewhat normal pressures, and poor cooling after a system has been messed with I would suspect it has air mixed in with the freon. Or the heater valves leaking, which you already checked. I would break it down myself and change the expansion valve and drier for good measure and evacuate it good before charging it again. | ||
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| ronm |
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Fruita CO | Doesn't sound like exp. valve to me, that's not what they do-I would guess air, like somebody said. As somebody else said, if the JD shop worked on it, it's their baby...I missed that point when I read this last night... | ||
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| scott nelsen |
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Leeds, North Dakota | pis's poor dealer, open system drier always, to many things going on here, gotta troubleshoot system, yes radiator ,oil cooler, evaporator need to be clean, ya got air flow, tells me need to put gauges on it, see whats going on, if compressor failed, got too flush all lines, replace drier and exp valve, bet it works fine, scott. | ||
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| Adrian |
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South Georgia | Thanks for all the suggestions. When I tightened a fitting and added freon, the system wasn't completely empty, and it was in the field. I was just looking at obvious things to do to be able to finish what we were doing at the time. Yeah, maybe I should have taken it back, but I don't seem to have real good luck getting somebody to fix something the second time if they couldn't fix it the first time. I just carried my car to the front-end shop for the third time, and it still pulls to the left. I might carry it somewhere else, but I don't anticipate carrying it back there, as I think that's an exercise in futility. I'm supposed to have a drier and expansion valve waiting for me in town tomorrow morning, I'm going to replace them and pull a vacuum and start over. As far as I can tell, I don't have anything to lose, other than a little time and another $100. I really don't have the time right now to be doing it, but I didn't realize it still needed work until Friday. Yeah, I should have known that a vent temp of 70 wasn't good enough last time I worked on it, but I guess I'll know better next time. Thanks for all the help. AgTalk is a great resource! Adrian | ||
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