Mud in my Veins
Join Date: Dec 2000
Location: Memphis, TN
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Those cheapo conversions are not the right way to do it - that's why they don't get as cold. R-134a causes the mineral oil used with R-12 to congeal. The right way is to completely open the system, pour "flush" into all the parts, blow everything out with compressed air, pour PAG (PolyAlkaline Glycol) oil into the compressor, install a red capillary tube (it's sized to work with R-134a), replace the O-rings (~89 & earlier), put it all back together with a new accumulator/drier, pull a vacuum, do a leakup test, then charge it with R-134a to 23psi on the low side. It's also recommended to add a high pressure cutoff switch in the clutch circuit set to 475psi into the high side, but they're expensive. If you have access to an air compressor and gauges, and your own evacuator ($15 at Harbor Freight) to pull the vacuum, the whole thing only costs about $50-75.
83 Custom w/95 4.9L EFI, 78 NP435, 83 NP208, 83 D44IFS 3.07, 87 Ford 8.8ABS 3.08, Michelin LTX AT 31x10.50R15