Kubota cab tractors ac maintenance

[SidecarFlip]

So here we are in 2020 and my 2004 M9 has been exhibiting some interesting quirks. The ac stinks for one and the airflow from the vents has been getting less and less but cooling power is just fine, just hot enough volume and it has a distinct odor about it so...

I removed the roof. I've removed it before. Kubota installs all the climate control mechanicals up top on my unit (I understand they are now under the seat), enclosed there. Mine are not.

Last time I removed the roof (6 years ago), I lined the inner roof with Reflectix foil-bubble foil insulation so the climate control wasn't fighting the heat constantly (the roof is not insulated at all and the sun beating on it, really heats it up). it helped but as I said, airflow is becoming less and it stinks so..

I partially removed the upper unit cooling heating cover to gain access to the evap. The way it's designed, it's impossible to remove entirely without breaking the hard lines and removing the heater core which entails draining the coolant so I removed all the screws and bolts and propped the cover open enough so I could see the evaporator. It was basically solid mass of coagulated dust and dirt, no winder it stunk and no winder the airflow was reduced, don't see how anything could get through that mess.

After propping the cover up, I took a spritz bottle with purple ZEP in it and soaked down the evap and let it sit for a while. Then I took my pump garden sprayer with warm water in it and flushed the coil. Did that 3 times, making sure the stuff was draining out of the condensate tubes under the tractor, which it was and it was nasty. Took 3 applications to get the water to run clear. Once I had clear water, I buttoned up the shroud and replaced to roof but I also replaced the old sealing gasket which was shot and letting dust in.

I'd never cleaned it before. That won't happen again. I'll be cleaning it at least every other year from here on out.

Was talking to my good friend down the road who owns a huge seed operation and has a fleet of large cabbed JD's and he told me they do that every spring. Change the fluids and clean out the ac units.

I won't be lacking that aspect again. It not only smells good now (I changed the intake filter on the roof as well, but it blows hard and cold, just like new.

He was surprised when I told him I never cleaned it. His comment was "I'm surprised it even worked at all".

Little heads up if you have a cabin unit with ac....

FYI, the roof is secured with 10 threaded screws. Every other screw secures the roof and the roof screws are quite a bit longer that the others so if you remove one and it's short, the next one, either way will be a roof screw.

I imagine the underseat unit suffers the same fate, dust loading up the evaporator but I don't know the cleaning procedure on that.

 

[chim]

Thank you for that info. Although there doesn't seem to be a problem with mine, it's worth the effort to maintain it.

 

[SidecarFlip]

Kubota offers 2 filters. The standard pleated paper one (it's washable btw) and a charcoal one for herbicide / pesticide application. This time around I got the charcoal one.

Not sure if you can get them aftermarket, I just bought OEM. The filter was 45 bucks, the new gasket was 96 and the corner pads were 8 bucks each from my dealer.

My gasket and corner pads were completely shot. Hard and crumbly.

 

[lugbolt]

I do quite a few M8540/M9540 cab a/c services every year. If you do it all, meaning removal of the evap and heater cores for cleaning and cleaning of the box, then the condenser; then adjust the belt & reassemble/check the pressures, generally speaking if it's still a virgin system or even one that's been properly repaired in the past (not hacked), they work VERY well given that the cabin is a big greenhouse. Good quality window tint (not the junk most shops like to peddle) on the windows and the a/c system will run you out of the cab. One of my good customers' 9540, his dog rides in the cab with him and the amount of hair that is in the evap core is just horrendous. Zero air passes through. Filters are usually just falling apart.

 

[SidecarFlip]

I didn't pull the heater core on mine, probably should have in retrospect but that would have entailed draining the coolant to remove it. The roof mount unit is pretty compact and it's all crammed in there.

All I did was access the evap and clean and flush that. I doubt much got past that to the heater core, the evap sits on an angle in the housing, it was loaded. I've never cleaned it since new. Kind of interesting how the airflow slowly drops off and you just assume it's ok. I knew it wasn't when it developed a smell.

Clean and good now and blows ice cold. No swearing and sweating this summer.

Next time, I will pull the heater core as well, because it will be on a coolant change. Will be an at least bi-annual thing for me.

Had to do some work on the roof as well. Where the huck fasteners mount to the roof itself, all the holes were stress cracked and I've never stressed the roof either. I laid on fiberglass resin and fiberglass mat over the stress cracks. Kind of a weak mount system and I wasn't about to drop 1600 bucks on a new roof. Least the material the roof is molded from likes fiberglass resin and mat. Very secure bond.

Again, a few years ago I lined the entire roof with foil-bubble-foil Reflectix and that in itself made a big difference. When I did that, I didn't notice the stress cracks. Might have been there but I wasn't looking that close I guess.

The gasket was completely shot (I guess that is to be expected since it was from 2004). It came off in brittle pieces, same with the end pads.

I'll stay on top of it now.

 

[memtb]

Thanks Flip, I’ll be taking a look at that! memtb

 

[Ivalodgem]

I never got around to fixing my 5030; I found my problems were dirt and dust packed into the fins of the rads/coolers. I made an air wand with a 90 deg tip to slide in and blast it all out. Unfortunately, the screens don't seem to stop much of the dirt, and the plugging would happen every day. I can't get the plugs out unless I get the air right on it. As long as that is clean, I get ice cold freeze you out a/c. As soon as it's even 50% plugged, the a/c goes, and the temp gauge starts creeping up. Nothing worse than trying to finish the last bit of field, and you have to run your heater wide open and cook yourself out of the cab.

 

[DustyRusty]

Be careful what you clean it with, because the cleaners can attack the metal of the condensing unit. I use a product specifically for cleaning the coils from Simple Green, that is used in the refrigeration trade. That way, I know that what I am using will do no harm, that will go unseen until the damage is too late to repair. Some of the "purple" cleaners are extremely harsh chemicals, and that is why they clean so well.

 

[Ivalodgem]

Be careful what you clean it with, because the cleaners can attack the metal of the condensing unit. I use a product specifically for cleaning the coils from Simple Green, that is used in the refrigeration trade. That way, I know that what I am using will do no harm, that will go unseen until the damage is too late to repair. Some of the "purple" cleaners are extremely harsh chemicals, and that is why they clean so well.

I never got around to fixing my 5030; I found my problems were dirt and dust packed into the fins of the rads/coolers. I made an air wand with a 90 deg tip to slide in and blast it all out. Unfortunately, the screens don't seem to stop much of the dirt, and the plugging would happen every day. I can't get the plugs out unless I get the air right on it. As long as that is clean, I get ice cold freeze you out a/c. As soon as it's even 50% plugged, the a/c goes, and the temp gauge starts creeping up. Nothing worse than trying to finish the last bit of field, and you have to run your heater wide open and cook yourself out of the cab. For more good information about this, I read on the site https://www.socool.sg/why-is-your-aircon-not-cold/.

 

[DustyRusty]

Try making some type of external filter that you can remove or brush off, to keep the dirt from accumulating on the coils.