Kubota Grand L 4610HSTC A/C

[bgott]

Insulate the roof, tint the windows and run an electric fan on the condenser that comes on with the compressor. Also make sure you don't have too much 134A in the system. You want your compressor to cycle down in the low 20 PSI range on the low side, if somehow or another a R12 cycling switch or expansion valve was installed you aren't ever going to get it to cool right. R12's low side is around 32 PSI. Was the tractor ever damaged to where someone might have changed the condenser? When they started running 134A in cars they had to run extensive shrouding to get airflow through the condenser, they also used multi- pass condensers to get it to work. Then again, the system might just be undersized for the heat load. Good Luck!

 

[frank_f15]

was wondering when somone was going to mention the phogene gas? also r12 and 134a are not that much different on the PT CHART. so a system designed for r12 should work fairly well if changed over to 134 and done properly. R12 is still available but only to EPA certified people. 2 things will cause an a/c to work then cut out, and then work again, 1) low refrigerant charge,2) high head pressure. if neither of these is the problem then the system design might be too small. i state again that the dealer should have someone there that should be able to find the problem. if it is low charge, that sholud be easily found, if it is high head pressure it could be not moving enough air across the condenser, or it could be over charged or there might be air in the system, air is a no,no.. it is non condensible and needs to be removed. just throwing things out there, hope it helps and sorry for the long post /forums/images/graemlins/blush.gif

 

[_RaT_]

MJB, if freon (R12) is heavier then air, how does it harm the ozone layer?

 

[CTyler]

Hi Rat, chlorofluorocarbon gas is heavier than air and will displace oxygen. Not sure if it combines/breaks down with the nitrogen etc.. in the atmosphere and rises. Or if its just light enough for heat wind etc.. to get it up there.

 

[ns_in_tex]

Brad,
I think my Kubota manual says low pressure sensor is set to 28.4 psi.

 

[frank_f15]

RAT; it is the chlorine in the R12 that does the dammage. chlorine is the culprit that destroys the ozone, ever wonder what the millions of swimming pools in the word, contributes to this effect? i had a techinical paper on the subject that explained it in detail, but will be darned if i can find it /forums/images/graemlins/frown.gif must be old age) /forums/images/graemlins/grin.gif /forums/images/graemlins/blush.gif

 

[_RaT_]

Well now that is interesting. I should think that chlorine use if anything is up and now there are reports that the ozone hole, specifically that over Antartica is getting smaller.

 

[5030]

Patrick:

Here is what I did. I added shrouds per se' on each side of the evap, extending back to the radiator screen. I also added the WOG valve. It's about 90 and VERY humid here today. With the tractor idiling in the sun, the temperature got down to 61 degrees in the cab. The condenser in the roof is putting out water like nobody's business. It's uncomfortable to hold your hand in front of the windshield vents for longer than a few minutes. I had to back the temperature control down a bit to even the temp at 72 degrees and the compressor is NOT cycling very much, it just stays engaged. It looks a bit cobbly in the pictures, but it WORKS FINE. I had to be careful where I drilled the holes in the brackets on the sides of the oil cooler so as not to interfere with the hoses. Other than that, it's a snap. It's obvious that the concentrated airflow through the evaporator does the trick. I must have been leaking a little coolant through the control valve too. With the WOG valve on the input line, no coolant gets to the heater core. Just like my big truck now.

 

[5030]

Here is a picture of the other shroud. I took an old discarded mudflap and a box knife and tailored them to fit. If you look closely, you can see the top of the evaporator and the relationship to the rubber shroud or airflow director.

 

[5030]

Here is a picture of the WOG valve. It's a 3/8 inch, 1/4 turn. I used nylon barbs with 3/8 pipe thread ends threaded into the valve. The line in the picture is the feed line for the heater core in the cab.

This setup really concentrates the air through the evaporator. It also increases the airflow through the oil cooler too. That's an added benefit as the 5030 generates alot of heat in the UDT fluid with the hydro.