L4610HSTC A/C not cooling

[tom9961]

I finally got to do some of the fixes 5030's shared with us to get my A/C to cool better. (Thanks 5030) I did everything but install the wog valve. It still does not cool during the hotter part of the day (midday). And when the cooling goes, the temp gage starts showing that my tractor is over heating. The gage will climb all the way to the red line if I don't stop and allow it to cool down. This again only occurs during the heat of the day. If I start early in the day and work untill dark the A/C and cooling work good in the morning and good again in the afternoon whe the outside temp starts cooling. Times that it seems to work good are up to 9 or 10am and then after 5pm.
1. How are the rest of you doing with your A/C
2. Anybody else running hot?
I have taken it back to the dealer several times to have them try and fix the promblem while under warrenty. They just keep cleaning the screens and flushing the radiators and trying to charge me for the cleaning. They said the Kubota man was there the last time and told them is was only dirty radiators. When I went back to pick up my tractor I told them that was a lot of bull and that just cleaning the radiators was not going to fix it.
Guess what it did not. Its back after two days of trying to use it oo bush hog one day and do fel work the 2nd day. Its been there going on 3 weeks and they still have not done anything to it! So I told them last tuesday when they said they were not set up to bush hog or run the tractor for long periods of time to replicate the problem that that was not my problem and they had one week to fix my tractor or I was going to turn the issue over to the attorneys. Thet then called me on wednesday and told told me that the Kubota man was on his way to look at another HSTC that had the same trouble and see what had been done to fix it. Well to shorten this gloomy story, friday they told me the Kubato man had called them back and that they were going to relocate A/C and transmission coolers. Rearrange them somehow or another. The K man told um this is what fixed the other tractor.
What do you fellow tractor enthusiast think.
Has anyone had any luck with their dealers fixing the problem?
How do I contact Kubato by phone?

I just want my tractor working so I can spend some quality time with it.
Frustrated and missing my tractor!

 

[5030]

Tom:

I just got a huge questionaire from Kubota in California. I believe they got wind of my home brew fix and want the details.

I am going to send them details and pictures. My 5030 never gets any farther on the temp gage than one segment past the middle and last time I used it was to round bale wheat straw and it was 90+ degrees out and I worked it's butt off for 10 hours straight.

I think maybe your thermostat is either sticking closed or partially open and not allowing full flow of coolant. Why don't you ask your dealer to replace it or replace it yourself. Thermostats are easy to test. Get a thermometer and place the thermometer in a pan of water with the thermostat. Begin to heat the water and note the temp on the thermometer. Most thermostats begin to open at 180 degrees and should be fully open at 210 degrees. The thermostat should have a temperature gradient stamped on the housing. That's the temperature it should begin to open at. If at 210 degrees it's not full open, replace it.

I'd also put the ball (wog) valve in the heater line like I explained in my thread. That eliminates any coolant from getting to the heater core in the summer.

I don't know how your dealer could locate the ac heat exchanger any closer to the radiator without extensive modification to the front supports. Besides, if the unit was tight against the radiator, you couldn't get the chaff from between the radiator and the heat exchanger and you'd have to eliminate the intermediate screen. I think, from my own testing, that shrouding the heat exchanger and oil cooler is the way to go.

I really think your problem is the thermostat or remotely, the water pump. I know your tractor is new like mine, but mistakes are sometimes made at the factory. Your dealer should be more attentive to your problem.

Monday, I'll call Kubota's regional office in Columbus, Ohio and see what they say too. That's in addition to the questionaire.

 

[5030]

Tom:

I never put in the thread, because I added it later, I also added another peice of rubber that extends from the top/front of the radiator down at an angle to the ac heat exchanger. I made 2 small brackets and mounted them to the bolts which hold the intermediate screen assembly in place. I bent them at an angle to allow the rubber to close the gap between the radiator and the heat exchanger. When you run the engine at any rpm over 1200, and put your hand in front of the heat exchanger between it and the oil cooler, you can really feel the air moving through them.

If you need a picture, I can take one and post it for you.

 

[tom9961]

Well it looks like 5030 and I are the only people that ever had any problems with the A/C and or running Hot. /forums/images/graemlins/confused.gif
Thanks again 5030 for all your help. I will let you know what happens with the dealer and their fix. I am gouning to carry over the photo you sent and see if that would help them.
The only thing wrong with this is You and I should not be having to tell Kubota how to fix there tractors. With what we paid for them they should work as advertized. /forums/images/graemlins/mad.gif

 

[ns_in_tex]

Tom,
I have an L4610 HSTC with 480 hrs on it. I think the only time I have ever seen temp over 1/2 mark was when coils were dirty. I do wish the ac had a little more capacity. I did read another tbn'ers info & put a couple of cardboard side flaps in as I understood (thanks 5030 if that was you). It seemed to help a little & I do not have a problem when mowing at pto speed. I still wish I could find a way to get pto speed up with engine speed lower (for less noise & efficiency) then I would probably need still more air conditioning.

 

[tom9961]

Neal what mower are you using? My dealer sold me a woods BB6000 said it was the size unit that I needed according to what I told him I needed it for. I asked him several times if it was to much mower and he assured me that my tractor could handle it.

 

[tom9961]

This is a discription of how my tractor behaves:

Somewhere around July 16th or 18th ,2003 I brought my Kubota L 4610 HSTC in for service because it was running hot especially when I was bush hogging and the air conditioner was not cooling during the heat of the day.
When I was called on July 22nd or 23rd to pickup my tractor, I was told that the Kubota service man was there and that he had checked it and it was just a dirty radiator, a dirty ac coil or whatever you call the ac radiator and a dirty hydraulic radiator. When I saw that I was billed for the cleaning of the radiators I told Roger this was not right because dirty radiators was not the root of the problem and that the cleaning was not going to fix the problem. Roger told me to take the tractor and try it to see if the cleaning fixed the problem. At least we knew that the radiators were all clean and if the problem persisted I would not owe the bill and they would have to try something else. I agreed that sounded fair although it probably meant that I would have to haul my tractor back to the shop when it was proved that the cleaning didn’t resolve the problem.
Well it did not fix the problem!
The following is a brief description of how the tractor performed on July 25th.
At 8am I began bush hogging a pasture that was between 3 or 4 acres. It was heavy Bahia grass and other weeds. It all was 3 to 4 feet tall. I was in the complete sunshine the whole time that I was clipping. The grass was thick enough that I was forced to mow in low range most of the time and at a very slow forward speed in order not to lug the engine. The first hour or two the AC was cooling so good that I had to adjust the temp control so as not to be too cool at the lowest fan speed. During this time the tractor temperature gauge showed no problem with overheating. By 10:00am the AC had to be set for coldest temp and the fan speed had to be increased to the second setting. The cab continued to warm and the AC air was not very cold and the engine temp gauge climbed to a little beyond the 2/3s mark. By 12:00pm I had to turn the fan speed on high. The AC air felt like a fan blowing around warm air in the cab. I don’t think it was cooling at all. The engine temp gauge climbed toward the red zone and nothing I tried would stop it. I had to shut down the tractor and allow it to cool before continuing.
Throughout the mowing session I repeatedly stopped and cleaned the radiator screens and air vents in the engine cover. Early in the session, say mid morning it seemed like it helped a little, however, by midday it did not help prevent the engine from running hot in the least.
After stopping several times to let the tractor engine cool down I completed that mowing session and loaded the tractor to move to another location. By 5:15pm I was bush hogging another pasture. Total cool down time between sessions and moving the tractor by trailer was about 1½ hours. The outside temp was now cooler and part of the 2nd mowing early on was in the shade. With the AC on high speed and set to the coldest temp setting it was blowing cold air and cooling the cab fairly well. The engine temp gauge climbed a little past the 2/3 mark and stopped climbing. I mowed until 8:30pm that evening and just the opposite of what happened that morning occurred. The later it got the outside air got cooler, it got shadier and it got darker. All this resulted in my adjusting the AC fan down to lowest speed and the engine temp gauge falling to below the 2/3 mark.

Don't know is mine a lemmon. What do you all think. /forums/images/graemlins/crazy.gif

 

[frank_f15]

not real familiar with the a/c systems on tractors, but from what u are saying and what others have stated, if it works ok in early morning and ok at evening when the ot is cooler, seems like the problem is when u get hotter air going across the condenser. if the condenser is not cooled properly either because of too hot air or not enough air, the discharge press will rise and then so will your suction pressure, the higher the pressure the warmer the cooling coil and thus it can't cool right. i beleive someone said they added flaps? what that does is force more air acroos the condenser thus lowering the pressure., i hope this makes sense?

 

[ns_in_tex]

Tom,
I have a 6' medium duty bush hog mower for the field & a 7' First Choice finish mower. I must admit I have not used the 6' bush hog as heavily as you describe, because I have a larger tractor & mower to do the heavy work with. I like to use the Kubota for trimming, in the tight spots, where lots of backing is required, or where the big 2 wheel drive might get stuck.

Also I think both the engine & cab cooling system are just bare minimum capacities. My larger tractor does not have to be cleaned near as often & produces much more cold air.

I have found when in dusty conditions, the cooling system needs a good cleaning more than once a day on the L4610. Maybe more than morning, noon & night. By good cleaning I mean, grill & side panels off, good air hose & possible water hose after. I keep a thermometer in one vent & when it stops producing 50/55 degree air, I go clean it & it seems to help.

 

[normde2001]

Tom, you guys do not have A/C problems, you have tractor overheating problems. I would ask the dealer if they flow tested the radiator, or do it myself. It may need to be removed and rodded-out by a radiator shop. Your A/C cooling is in a direct ratio with your coolant temp, assuming your fan is working.