82 K2500 6.2 Diesel Air Conditioning Ideas

[canadaboy25]

Hi all, browsing through the site I see a ton of threads about AC, but not much regarding diesels.

I've been fighting with the AC in this truck and losing, so I'm looking for ideas. The truck is a 1982 K2500 with a 6.2 diesel.

First, a description of the system. Originally the truck had no air and a 6.2 with the factory v-belt setup. I tore all of the air components out of a donor truck, modified the firewall, and installed it all in my truck. I had to fabricate my own compressor bracketry to make it work with the diesel. This setup sort of worked but I was constantly springing leaks. The last thing I did was buy a new R4 compressor and the system worked "okayish" for a bit.

A few years later, I swapped the v-belt system to a serpentine system from a 93 truck. This relocated the compressor to the top on the passenger side. So I had to install the compressor on the other side of the engine. The lines on the condenser also had to be bent straight sideways to clear the radiator. I blew all the oil out of the evaporator and condenser, and installed a new orifice tube. I also installed the compressor from the 93 since it had the serpentine pulley.

I charged the system up and after a few seconds, the shaft seal on the compressor blew out. So I swapped the clutch over to the compressor I had bought previously and recharged the system. I cannot get any cool air at all, no matter how much refrigerant I use. The low side is always way too high.

I am tired of screwing around with this. I have looked at aftermarket kits, but have seen mixed reviews on them. The other issue is that the kits all seem to come with a sanden compressor. This won't work with my serpentine system on the diesel since the brackets are two large cast iron pieces which also mount the vacuum pump.

Does anyone have any ideas on how to go about fixing this mess? The system is such a cobble of different parts and years, that buying new parts is a crap shoot. I am open to an aftermarket unit so long as I do not lose my glove box, and the compressor will mount cleanly to a 6.2 diesel with a serpentine setup. I would like to just buy a bunch of new stock parts, but I cannot seem to figure out the combination of years to buy for to make everything work together.

Knowing how much oil and refrigerant to add is also difficult since the truck is an 82 but the engine and compressor setup is a 93.

I'd like to hear your thoughts/suggestions

[Dead Parrot]

Might check over on the Steel Soldiers site. There is a forum there dedicated to the CUCV, which was in the basic form, an 84 K30 with 6.2 and a 24V starting system. There was also a Blazer version as well.

https://www.steelsoldiers.com/forums/cucv.47/

I have seen more then one thread on adding AC as the military version was heat only.

[kwmech]

Sounds like you reversed the lines on the compressor.

[canadaboy25]

Originally Posted by Dead Parrot

Might check over on the Steel Soldiers site. There is a forum there dedicated to the CUCV, which was in the basic form, an 84 K30 with 6.2 and a 24V starting system. There was also a Blazer version as well.

https://www.steelsoldiers.com/forums/cucv.47/

I have seen more then one thread on adding AC as the military version was heat only.

That is a good idea. I will check it out. Thanks

Originally Posted by kwmech

Sounds like you reversed the lines on the compressor.

It isn't really possible to do so on the R4 since the lines are a 1-piece block that bolts to the back. And either way, the large line is suction and the small line is pressure, and they are hooked up properly.


Yesterday I took the truck for a 2 hr trip for the first time after installing the new compressor, and the AC kind of worked.

It was about 23°C outside and I was getting 11°C from the vents at highway speed. However, as soon as I slowed down, the air coming from the vents was just ambient temperature. Today I made the same 2 hr trip with 26° outside temp, and the lowest temp from the vents was 14°C. These were pretty cool days, so not a good test for AC. But the cooling disappearing completely when slowing down is clearly an issue.

The condenser is perfectly clean and the fins are straight. But it does not cool at all at low speed. The truck runs at quite high RPM on the highway, so I am wondering if the new compressor is weak and the extra RPMs get it to start making pressure.