Air Conditioning 3720 CAB

[JasonMac]

My A/C doesn't seem to be cranking out the cold air like it should. I checked to "Feel" any wind leaks in the roof seal.. Filters and Screens are clean as could be. A/C definitely kicks in when you throw the switch, because you can see the Tachometer do a little drop in engine speed.

So do you guys think I just need more Refrigerant put in my system?

When I was going through that long ridiculous ordeal with my service manager, I kept telling him to check my A/C out.. and it wasn't working up to par as of last summer... (heat worked fine this winter, that's why I don't think it's a roof leak).... He kept telling me everything was fine... and I only needed a new cab filter, even after my last cab filter was only like 6 months old, with hardly any use on it at that given time. I asked him, and he said everything checked out okay..

Now today, I had to do a brush hog job. And the A/C was colder than using just the vented air.. but it wasnt "Cranking" cold.. so I was for the first time actually beading a few streams of sweat, brush hogging today..

Would a regular place that deals with topping off A/C systems in cars be able to do this for me, if I drive the tractor there? Or what should I do?

That is if you think it is only low on Freon.....

thanks,

Jason

 

[Willl]

If it IS low, then you have a leak.

And yes, if they can do autos, they can do tractors.

Got a Thermoking shop near by ?, they can/will help also.

 

[nmu98]

I have found that if I do not blow my cab filter out every time or two the AC will decrease in its efficiency. It is always very dusty, even when I do not work in that much dust. The placement of the intake seems to be right around where all the dust stirs up.

If you are not blowing it out often, save you money and try that before taking it to the shop.

 

[ddivinia]

How hot is it outside?

How much is it cooling?

I think they say it should drop the temp 20 degrees or so. I find that both my 5525 and 4720 will drop the temp that much. Keep the intake filters is important, but keeping the condenser clean is even more important. Have you check it?

You might want to get a thermometer and get actual numbers for inside and outside.

D.

 

[jenkinsph]

John Deere claims a 30 degree drop in temperature from ambient, when I purchased my 4520 I checked it at the dealership before delivery and measured 22.6 degree drop. Not great but enough to cool down a cab when working. I would make sure the condenser, radiator, and coolers up front are all clean in addition to the cab filter. Do this first before taking to a shop.



Steve

 

[ddivinia]

I'll ask my dealer what the real number is that they target.

D.

 

[jenkinsph]

I'll ask my dealer what the real number is that they target.

D.

Not to derail the thread but what was wrong with your AC earlier?


Steve

 

[sunnyside360]

I've had my 3720 cab tractor about two years and can tell you from experience all the items mentioned above should be done prior to getting too excited and/or spending any money. Blow compressed air thru all coolers up front and the cab air filter. If the A/C still seems anemic I'd check the roof seals. Several threads exist on 3720 A/C and most if not all issues have been traced to one or more of the above.

 

[radman1]

I've had my 3720 cab tractor about two years and can tell you from experience all the items mentioned above should be done prior to getting too excited and/or spending any money. Blow compressed air thru all coolers up front and the cab air filter. If the A/C still seems anemic I'd check the roof seals. Several threads exist on 3720 A/C and most if not all issues have been traced to one or more of the above.

You are right on. Check out all of the things listed above. Initially I had a problem with the cab air box sucking in air and not heating well but the same would happen with the a/c. Month ago, I was getting poor cooling. My brother had mowed a week earlier and plugged up the rear air filter. He didn't notice the cab was warm. I noticed it immediately that it was short cycling and not cool at all. Cleaned filter and back to normal. I do have to add a little R134 to my JD 3720 A/C each year. Must be a very small leak somewhere. I do it myself but can only check the low pressure side. I typically get a 30 degree temp drop. Last time I checked it was blowing 47F on an 80F day in the sun. When my system is charged, it keeps very cool on even the hottest days.

 

[sunnyside360]

You are right on. Check out all of the things listed above. Initially I had a problem with the cab air box sucking in air and not heating well but the same would happen with the a/c. Month ago, I was getting poor cooling. My brother had mowed a week earlier and plugged up the rear air filter. He didn't notice the cab was warm. I noticed it immediately that it was short cycling and not cool at all. Cleaned filter and back to normal. I do have to add a little R134 to my JD 3720 A/C each year. Must be a very small leak somewhere. I do it myself but can only check the low pressure side. I typically get a 30 degree temp drop. Last time I checked it was blowing 47F on an 80F day in the sun. When my system is charged, it keeps very cool on even the hottest days.

I haven't had to add refrigerant yet. JD dealer checked it and it was ok when they had it to replace the roof seals last fall. The A/C now works well as long as I keep debris out of the cooling fins up front and keep the cab air filter clean.