Kubota Grand L 4610HSTC A/C

[patrickg]

D.A.R.Y.L. (Sorry, I liked that movie...)

Yea verily, I read your post with great interest and am anxiously awaiting your initial findings regarding the mod(s).

If I don't get results with ensuring hot water is turned off and freon fill is correct and the like then I was thinking of adding an electric fan out front of the condensor with or without a duct (as required) blowing toward the engine, with a screen on its suction side so as to reduce the build up of stuff on the existing screen. If I do the fan, I'll probably screen in the entire front of the tractor. It would be easier to remove a large screen out in the open that the two little screens in behind the batt and tucked away where I get burned fishing them out.

Pat

 

[CTyler]

</font><font color="blue" class="small">( Another thing I wondered about is pulling the cab top, which I think is just raw uninsulated plastic (which all the return air has to pass under) & insulate it with something. Probably 1/4" styrofoam would help. )</font>

I would go with a reflective type insulation since most of that heat is radiant. It will be a night and day difference as far as the cap is concerned.

 

[ns_in_tex]

Pat,
After reading your post last night, concerning air flow across the condenser coil, I took a closer look at mine. If you notice, the front grill is just a lot of little holes which is not a very high percentage of free air space. It got me to wondering if this were a restriction, since you said yours worked ok driving down the road near top speed. I thought when I get a chance I would compare operation with the front grill removed to rule on that question.

Also, it seemed as if you might be having excessive belt slipping. Too much freon might cause
1. Liquid back to compressor ( Stalls compressor)
2. Not enough room in the evaporator to expand (less cooling)
3. Cut compressor off if it has a high pressure switch

Just food for thought

 

[5030]

Patrick:

I guess I'm out of the loop as far as movies go so I don't know what movie that is. What I do know is that when my tractor is cold as in coolant, the ac works great. as the coolant warms up, the ac diminishes. I would surmise that I have hot coolant leaking past the flow control valve. Thursday, I'm going to address the problem.
1. I am going to install a WOG ball type 1/4 turn valve in one water line, probably the one on the right hand side of the engine (fuel pump side) as it is very accessable with the hood up, even with the side panel attached.
2. Fabricate a shroud between the evap coil and the radiator. I'm going to make it out of rubber and make it butt to the radiator screen, while still being able to remove the screen easily.
I compared the evap coil on the 5030 to the one on my 350 Ford and the one on my 5030 John deere. Both the Deere and the ford have the coil mounted TIGHT against the primary radiator. I think the coil is too far away from the radiator and then the oil cooler is really too far away from the evap coil. If you look at the way they are mounted, you will notice that the mounts take advantage of the subframe which holds all the sheet metal in alignment. It would be very hard to remount the evap coil as the lines are hard. The oil cooler is another matter as the lines are rubber as it's on the suction side of the pump. I think by concentrating the airflow through the evap coil and the oil cooler with a shroud, the evap coil will transfer more BTU's at a higher rate. It is odd that the units are so far away from the primary radiator. I would imagine, that without a "clean" air path, much turbulence is present between the oil cooler, the evap coil and the primary radiator. I am hoping that the shroud and the complete physical shutoff of hot coolant should handle the problem. I checked the ancillary line coming from the water pump, to the cab and back to the block. It is very similar if not exactly like the setup on my E-model caterpillar in my '99 Western Star. That has a provision, from the factory for complete shutoff of hot coolant to the heater core in the summer.
I will keep you and this thread posted with results and will take pictures of the instillation. I hope it means less anti-persperant for me.

 

[5030]

NS and Patrick:

By the way, guys, it's not Freon any more, the only Freon is in the control of the Federal Gov't. It's Refrigerant 134A. It's a synthetic and it does not have quite the heat transfer capabilities of Freon. R134a for short.

Freon is absolutely the BEST fire supressant known to man. The only drawback is it's leathal and a detriment to the ozone layer and we don't want to deplete the ozone layer do we? Without the ozone layer, skin cancer would run rampant, doctors would get richer and we'd get poorer. /forums/images/graemlins/smirk.gif

 

[rockyridgefarm]

A couple of ideas....

I think the reflective isulation on top is a great Idea. Or paint the very top of the roof. Around here the school bus roofs are being painted white. Going from yellow to white will drop about 20 Deg. inside. ( thaey aren't insulated....)

The electric fan would not load your engine (+) Not sure about the cowl/ducts...

Window tint sure helps

Obviously I am not trying anything like this on my setup...

Sorry to hear it isn't working. My bet is the system was designed for an older refrigerant, and modified for the present wonder from the epa...

 

[MJB]

Freon, or R-12, is not lethal. It can kill you by displacing oxygen if the concentration is high enough, but it is the lack of oxygen, not the presence of R-12, that is doing the harm. This oxygen displacement is what makes it work good on fires too. You could suffocate equally well in a dense cloud of nitrogen gas, which makes up 78% of the air we breathe. R-134A would work equally well for the same reason. The old Halon fire extinguishers worked like gang busters on fires, but they are actually many times worse than freon on the Ozone layer. Also, you can still buy R-12 if you have a license, which I do, but the cost has gone out of sight.

 

[MJB]

A system designed for R-12 would need to have a bit bigger condenser in order to get the same performance with R-134A. If it has not already been done at the factory you might be able to rig up a subcooler using the condensate water off of the evaporator to increase the performance of the unit.

 

[bgott]

The problem with using freon, R-12 anyway, as a fire suppressant is that it forms phosgene gas when exposed to flame. Phogene gas is poisonous, they used it as a chemical weapon as least as far back as WW1.

 

[5030]

Not on the original subject of this thread, but I did mean to say that freon displaces the oxygen, so you suffocate. R134a is not as good as R11 or R12 at transferring BTU's. I don't think that Kubota would update an old R11-12 system to 134a. I too have access to R11-12, but it is extremely expensive, it's actually cheaper to refit and reseal to run 134a, with, of course a slight loss in cooling capability.

I'm going to dissect my 5030 tomorow. I'll let everyone know how it turns out. I am very desirous of about 30 degrees below ambient at the vent on high.

It's a bugger to remove the roof panel. It has about 12 torx type screws in it. I may put reflective foil (adhesive backed) on the underside of the panel, but I believe that a complete external, physical shutoff of coolant (water) coupled with the shrouding will achieve my goal. I'm an optimist.