Grand L 3430 a/c issues

[fegarex]

My Grand L 3430 has 350 hours on it and the a/c isn't nearly as good as it was new. The air is cold but the "amount" of air coming ot of the ducts seems much less than before. I've cleaned the rear filter, checked to see that the fan has all three speeds and pulled the roof off to see that the cables for the ducts are working right. Everything appears correct but there just doesn't seem to be much air coming out of the ducts. I've tried the fresh air and recirculate mode and it doesn't make any difference.
Anybody been there?
Thanks.

 

[Happyman]

Sorry....I sit in the great wide open. I sometimes wish I had a cab

 

[mark2610d]

Two things come to mind. Your fan (blower inside cab could be slipping on the shaft, possibley a loose set screw). Maybe your a/c coil inside is freezing up because of low charge? Does it do it when you fist turn it on?

I have the same tractor and have 500 hours and it still works as good as the day I bought it with plenty of air flow. You for sure have someting wrong somewhere.

Did the air flow get faster each time you selected a faster fan setting?

Mark 3430hstc

 

[fegarex]

I pulled the roof off and watched the blower fan and it increases on each setting and isn't slipping. I am going to check the temp at the outlets tomorrow and see what that is. Today was only 70 something here and sunny and the cab never got really cool. The air coming out of the ducts seems cold but just not enough of it. Perhaps the coils are plugged with dust but it really isn't run in extreme dust conditions.

 

[art]

You might need to top off the system. You could have a small leak that let enough freon out to hinder the performance of the system.

 

[fegarex]

I checked the temp at the ducts this morning and it was 56 degrees. The dealer said that was fine. The fan sounds and looks like it is running at the proper speeds so I guess I will have to pull the roof, a/c box and see if things are plugged up there.

 

[WTA]

On all the ones I fixed with this problem there was somethign, usually dirt, plugging the evaporator. If you have already figured out how to get the roof off then go ahead and blow out the evap real good. Then try to run it with the AC fan on low while watching the evaporator. If it turns into a giant block of ice then your charge is low or you have air in it.

The capacity on these tractors is much smaller than most cars so I do not recommend charging it unless you really know what you are doing with anything other than a good gauge set that is purged or a recovery machine. It does not take much air at all to mess it up.

 

[fegarex]

That's my next move. Getting the roof off is easy but it looks like the cover on the evaporator is more involved. I have a parts book somewhere and will look to see what it takes. I tried an air hose and "back blowing" through the ducts but it didn't seem to do much good. I'm guessing I wasn't getting close to the evaporator.
Now... I need to find the time to do this between mowings!!

 

[texbaylea]

As a matter of interest of interest. What freon is used in these systems. R134a or ?.

Vernon

 

[art]

For a number of years it has only been R-134

 

[dbk123]

I've got a 5740 that creates a lot of ice in the AC system after running for some time (I can tell because there is a lot of water coming from the drain tubes on either side of the cab when I shut it down). Is this normal or a sign of air in the system or low refrigerant?

-dbk123

 

[fegarex]

Update to this issue. Never had enough guts to pull the top off the a/c unit until this spring when things were getting worse. Anyhow I got a service manual and taking the top off the unit wasn't as bad as I thought and indeed it was plugged with dirt. I'm guessing the combination of moisture and dust created a "mud' in there. A good cleaning with an air hose cleared it and its working like new again. I'm guessing the next time I do this it would take 30 minutes or less to do.