LMTV Air Conditioner

[scottmandu]

Afaik all cat powered FMTV used a v belt for the ac compressor.

 

[tterbo]

scottmandu, are you getting my PM's? Trying to get one of those pulleys from you...

 

[bikeracer917]

I just wanted to say.... That ringpower sells the crank pulley. Its right at 190.00.

 

[coachgeo]

I just wanted to say.... That ringpower sells the crank pulley. Its right at 190.00.

Is ringpower a member or vendor here orrr?

ahhhh.. quick search.... Nope; nota either, tis a CAT dealer in FL. That means other CAT dealers may can get them too, assuming it is the correct pulley. CAT Part #?

 

[Duckworthe]

Thanks for this post. Would you PM me on this topic? I need one.
Thank you,
Eric

 

[scottmandu]

Is ringpower a member or vendor here orrr?

ahhhh.. quick search.... Nope; nota either, tis a CAT dealer in FL. That means other CAT dealers may can get them too, assuming it is the correct pulley. CAT Part #?

The pulley (as supplied to the Govt) is made by Red Dot as is the rest of the A/C system.

There is a triple groove pulley listed in some of the CAT parts manuals. This might be an option is everything lines up. The back two grooves can run the alternator and the front groove can run the A/C.

 

[bikeracer917]

Sorry. I should have been more specific.... Ringpower is the caterpillar dealer. Just find a close one to where you live. Give them your engine serial number and tell them what your looking for.

 

[bikeracer917]

Not sure what engine this is for but the part number for the v belt pulley is mfr-62534-rd-3-11669-0
My part number is 2981308. It's for a Cat c7

 

[Kiki]

What amount of refrigerant is used in the system? i just serviced mine with 3.5lbs of R134 and it seems like it was more than it needed.

 

[bikeracer917]

Not sure the exact amount. I will ask my friend in the army.

 

[Kiki]

Not sure the exact amount. I will ask my friend in the army.

Thanks, i am about 95% complete with the install of the AC, just waiting on a red dot binary switch and making 2 brackets for the condenser. looking at the pressures i have a good differential between high and low but the temp at the outlet is only 50-60 degrees F with the outside temp of 80-85, i thought it would be closer to 40 with the vent being so close to the evap.

 

[bikeracer917]

Does the condenser unit have all the wires needed for installation? My binary switch has 3 prongs. I would hope that the condenser wiring harness would have the appropriate connector. Do you have any pictures of the connections?

 

[Kiki]

i am using harness RD-4-6001-0 and just making connections as i will need to ( I am using Wiring Schematic R-5750) and then sourcing a 2 wire Binary Switch (RD-5-4640-0P) that opens at 30 and then again at 300 which should provide protection needed for the AC system. as for the switch on the purple/purple i dont see much need for this switch as all of my autos run the condenser fan anytime the AC is tuned on. that and I have put a 140-14/260-28 alternator so power isnt an issue.

 

[tburk49760]

Thanks, i am about 95% complete with the install of the AC, just waiting on a red dot binary switch and making 2 brackets for the condenser. looking at the pressures i have a good differential between high and low but the temp at the outlet is only 50-60 degrees F with the outside temp of 80-85, i thought it would be closer to 40 with the vent being so close to the evap.

what gas are you using. These early systems were designed for r12. 134a will reduce capacity significantly.

 

[Kiki]

R134A but i think that i will try something else as i checked the temp at the evap inlet and it was only 60 F so i will evac and maybe loo into the expansion valve as i think it should have been closer to 40 f at the evap inlet. thats good to know that this was originally an R12 based system.

 

[Keith Knight]

I used 134a and the coldest it will get is 50 degrees measured at the air vent, which was a little disappointing as I was expecting 40 degrees with such a large condenser.

 

[mkcoen]

what gas are you using. These early systems were designed for r12. 134a will reduce capacity significantly.

R134A but i think that i will try something else as i checked the temp at the evap inlet and it was only 60 F so i will evac and maybe loo into the expansion valve as i think it should have been closer to 40 f at the evap inlet. thats good to know that this was originally an R12 based system.

R12 was being phased out by the early 90s so doubt they were set up for that. My compressor specifically states it's for R134a.

 

[tburk49760]

The early 134a compressors were just a rebadging. No internal differences that I'm aware of. R12 is a way better refrigerant. If you can find it.

 

[Keith_J]

The Sanden SD7 series was never made for R12. Yes, Sanden was making R12 compressors back then.. Besides, the oil in the system is for 134.
Novices confuse temperature with cooling capacity. And this is air conditioning, not air cooling. You must know the dew point when making temperature measurements. Psychrometric tables ring a bell? Water has a very high heat of vaporization. So humid air will greatly increase evaporator exit temperature. We assume air exiting the evaporator to be saturated. Knowing the dew point going in, one can determine the energy used to remove that water vapor and voila, performance verified.

 

[Keith Knight]

I know very little of AC systems. But what makes the difference between my 2003 Jeep Grand Cherokee AC blowing 40 degrees parked right next to my LMTV with a new AC and a condenser at least twice the size, blowing 65 degrees? Both of them in the Florida sun at 90 degrees and 82% humidity. I've also had two different AC shops start from scratch by vacuuming it out then re charging it with the same results.