Excellent history report and references to comp and txv designs. Your BIG ears cause concerns that most people never consider. Hard to hit the nail on the head by remote analysis w/o pressures. 1) 2000 Tracker had a small Denso evap matched to a sanden SDB very small 87 cc fixed displacement comp, t...

Vacuum = a lot to do about nothing. Modern compressor dual shaft seals have a outer elastomer above atmosphere pressure lip seal and a inner teflon compounded under atmospheric pressure seal. The inner seal is often scratched during sloppy or dirty service replacement (w/o a proper shaft seal protec...

Love Key Largo and scuba diving john Pennekamp coral reef offshore. The R-4 is too much displacement capacity for most Vintage Air A/Cs and avaliable condenser "real estate" space. Early SD 5H14 (508) used SP 20 PAG which was exactly same as GM PAG 100 single end cap lube. PAG 46 (SP15) do...

We could use the a/c system's old high volumetric efficiency Borg Warner York ( with back seating valves) that was mounted on the engine to evacuate the system on the side of the road. These old Yorks could squirt R-12 out the head gasket during liquid slugging, BW increased top dead center clearanc...

Vintage Air's book "How to Air Condition Your Hot Rod" explains how to match system component capacities so that the compressor capacity (displacement/swept volume and drive ratio) is not excessive. condenser energy rejection must match the evaporator heat absorption plus horsepower energy...

1) The manual control valve bleeds gas to control the crankcase pressure to change the differential pressure across the underside of the piston verses the piston top which in turn changes the swashplate cam angle or stroke and refrigerant mass flow. Early versions had internal filters which would st...

Syria could be a hot place to grow up. I designed and tested and trained retro fit installers for military a/c for Iraq at MIL spec 130 deg F ambient using Coriolis flow meters for refrigerant side capacity calculations.. Old Tech: Dad would replace the bucket of ice under the heater floor vent outl...

bohica and crazy single discharge valve on scroll can get trash under seat or rotate slightly away from discharge hole and still perform at 50%, but equalizes immediately. to see and repair valve problem : 1) Scribe/scratch line across front housing and also comp body as refrence for accurate reasse...

Time will tell if you are better off having ignored advice to get a genuine SD7H15 from Tim at A/C Kits?

only one belt is needed for 510 (162 cc) replacement SD7H15 (149.5) for R-134a and less vibration,
SD508 is only 138 cc.