JD 3720 Air Conditioning line pressures?

[Lebneh]

Would appreciate pictures of the trouble spots, the next time someone does some AC maintenance.

I've seen a lot of complaints about the roof seals. Does everyone just pop open the roof right away to check it out?

 

[JDneophyte]

Would appreciate pictures of the trouble spots, the next time someone does some AC maintenance.

I've seen a lot of complaints about the roof seals. Does everyone just pop open the roof right away to check it out?

I read in the forums here to do a test by blowing out a lit match (or using lit cigarette) and hold it near the cab roof seals with A/C running full blast (make sure doors are closed/back window). If the smoke goes in any where except the back filter/intake, there's a leak. I did this and found no leaks. Though in the end, I did take the cab roof off (with some help from family....not a one man job)....13 nuts (the cab roof has studs....tricky lining it up to get it back on). I wish I took pictures.....hopefully won't have to do that again.

 

[sunnyside360]

I concur. Did you get your cab cool eventually?

It is okay when set on max cooling. I've never had to lower the setting because it was too cold like some others with 3x20 cab tractors here on tbn. I'm also comparing it to a few other cab tractors I have owned over the years. JD dealer service checked the system when it was under warranty and replaced the roof seal. Refrigerant was also checked and deemed satisfactory. The A/C works the same now as when it came back from service and declared normal. So, after almost six summers I have to say it is acceptable.

 

[jenkinsph]

Glad you finally got it working that is good to hear.
The problem with internet forums is you don't know who to listen too. Rereading the thread cleaning the condenser coil was suggested many times and was the most logical answer. Very common problem to see in the hvac business and regretably the most common cure for all ac ailments is to add freon this is particularly rampant in automotive systems using r134a as it is available over the counter. Most other refrigerants require a license to buy making the overcharged systems less of a problem.

Most of us who are in the business know to check the entire condenser coil. Glad you followed up about cleaning behind the battery I will remember to be more specific next time. Good threads end with good follow up posts, sharpens everyone's minds. So thanks for the follow up post.

 

[JDneophyte]

It is okay when set on max cooling. I've never had to lower the setting because it was too cold like some others with 3x20 cab tractors here on tbn. I'm also comparing it to a few other cab tractors I have owned over the years. JD dealer service checked the system when it was under warranty and replaced the roof seal. Refrigerant was also checked and deemed satisfactory. The A/C works the same now as when it came back from service and declared normal. So, after almost six summers I have to say it is acceptable.

I went over the cab seal after taking off the roof......and it's a very plyable foam rubber all the way around the perimeter. I could see if it was compromised, the two squirrel cage fan motors could pull warm air in, but you'd have to have a pretty good leak (say a 6 inch strip missing.....or the roof isn't seated properly). I also cleaned the evaporator coil while I was up there (not much in it, but why not long as I had the roof off). It's a great design up top, but under the hood they need to figure out a better way to cool the system down without every lawn mow/box blade in the dirt clogging it up...and ultimately shutting the A/C down due to overheating (or under performing as the refrigerant can't cool down enough).

I would love for one of us to figure out a permanent solution to this. If our wives cars did this after every trip to the grocery store.....you know a solution would be at hand.

 

[hanson1999]

Has anyone looked into sealing up around the hood area better? so all of the air has to come through the front grill. have done this on larger tractors that run in alot of dust and it solved lots of problems.

We even put a fine screen over the grill area so when the engine warms up its just to get out and sweep it off. Debris never gets through this way.

 

[JDneophyte]

Has anyone looked into sealing up around the hood area better? so all of the air has to come through the front grill. have done this on larger tractors that run in alot of dust and it solved lots of problems.

We even put a fine screen over the grill area so when the engine warms up its just to get out and sweep it off. Debris never gets through this way.

One of the issues the JD Mechanic noted when diagnosing my A/C problem was where the exhaust blows on our tractors: directly in front, blowing up dust and debris.

A fine screen (like a mosquito netting might help)......worth a try (like a truck bra or the like). I wonder if JD sells anything like that for us?

 

[JDneophyte]

Has anyone looked into sealing up around the hood area better? so all of the air has to come through the front grill. have done this on larger tractors that run in alot of dust and it solved lots of problems.

We even put a fine screen over the grill area so when the engine warms up its just to get out and sweep it off. Debris never gets through this way.

One of the issues the JD Mechanic noted when diagnosing my A/C problem was where the exhaust blows on our tractors: directly in front, blowing up dust and debris.

A fine screen (like a mosquito netting might help)......worth a try (like a truck bra or the like). I wonder if JD sells anything like that for us?

 

[shortthrow50]

One of the issues the JD Mechanic noted when diagnosing my A/C problem was where the exhaust blows on our tractors: directly in front, blowing up dust and debris.

A fine screen (like a mosquito netting might help)......worth a try (like a truck bra or the like). I wonder if JD sells anything like that for us?

my exhaust comes through the hood sticking up in the air and mine also came with a fine screen that quick disconnects off the front of the condenser. None of these two things do anything to prevent the conndenser from getting packed with debris when mowing. The debri goes around the screen unfortunately

 

[hanson1999]

ya that screen on the front of condensor is basically a joke. we need to stop debris from getting in the hood at all. I'm thinking some weather stripping and whatever else to only allow in air throught the front grill. then put finer screen over that if needed.