7080 A/C repair

The cab top didn't look as bad as a lot of them I have taken apart.

I bought 3 new compressors at a parts store liquidation for $78 total.  I think they went cheap as they are setup for V-Belts not serp belts.

The HR6 is a lot smaller compressor but it is setup with all teflon seals for the new refrigerants.

I used the original lower adjustment bracket, had to put a little more of a dogleg in it to line up belt.  Upper pivot is flat steel with a slight dogleg in it.  I set it up so it would use the original belt and it still has room for adjustment.  Rear is a piece of flat steel welded on with an old alternator adjustment bracket on it.

Couple of years ago I bought a hose kit and the cab fan from AP air.  The hoses fit perfect and this new fan is great, really quiet and moves a lot of air.  I would definitely buy that fan again.

I pulled out the evaporator and heater core.  Flushed both out, new heater hoses and valve.  New insulation on the cover plate, old foam was hardly there.  Flushed out the condenser also, the oil that was left in there was black??

I go to check power and nothing?  This is what was under the floor, I had to pull out the whole harness to get at it.  Looks like it was burn't, lot of wires were melted.  Spent 2 days fixing this right with solder and heat shrink.

Since I had the whole thing apart I put about 100psi of nitrogen in it and soaped all the connections then let it set overnight, no leaks.  I still have plenty of R-12 so that is what went back into it.  My hose hold about 3oz so take that off the total amount.  I put 8oz of oil in the system, compressor is a lot smaller than the A-6 so less oil.

I usually don't hook up the high side unless there is a problem.  I'm sure it was a little high as I had both side panels off, very little air flow across the condenser.

Its kinda hard to see but it is blowing about 38 degree air, should be good.  This was with a 84 degree day, 24% humidity.  I had the cab top off still and the right door was still off so when it is all closed up and drawing colder air across the evaporator will see how the expansion valve is going to change the superheat.  Usually if it is going great now there won't be a problem.

With the new barrier hoses and the teflon seals in the compressor this should last a long time.  R-12 molecules are larger than the newer refrigerants, the other ones I have done have no leaks for years.

Now to start on more cosmetic issues.