Ford F150 - A/C Compressor in 1989

I have a 1989 Ford F150, 5.0 V8. The compressor has went out and I have been considering going ahead and converting to the 134a refrigerant system. I had heard that a R-12 compressor will not work with a 134a system. Since I have to replace the compressor anyways, can I put in an after '95 compressor for it to fit properly? Any help would be great.

I think you mean 93 or newer compressor. 1993 was the year Ford changed over to R-134a.

I had not heard anything about the R-12 compressor not working on R134a so an 89 compressor should work OK but use all green "O" rings in everything.
The hoses are known to leak with R134a and the condenser is too small so the head pressure may be higher. I saw talk of the orifice tube that would need to be changed also but not 100% sure on that.

I just switched all of my trucks (5) over to Freeze-12 and never had any problems.

But I have also heard that if you buy a new compressor and you do not use R12 or R134a in them, whatever the case may be for your truck that the warranty will not be any good.

Make sure whatever compressor you buy has the right oil in it for what you are going to charge the system with (R-12 or R134a).

Ford uses PAG 46 oil in their R134a system but you need to put 4 more oz of oil in them then the system calls for or Ford says the compressor may go bad. This is in TSB 97-10-5.

Thanks very much. That helps a lot.

The later compressor probably won't fit onto your engine unless you also change the cast Aluminum bracket. If it fits, either will work fine, but obviously: the later compressor is preferred.

It's not the compressor that's incompatible - it's the older mineral oil in the system, so you must do a complete evacuation/recovery (take it to a pro), disassemble the system (it's pretty easy), pour in the flush chemical (~$20 for a bottle), blow it out, then reassemble putting 1/3 of the new oil charge into each of the compressor, condenser, & (NEW) accumulator. Then another evacuation before charging with 2 lbs 6 oz (30 oz per TSB94-19-20) of R-134a (Suva).

R-134a requires a red orifice tube for proper operation. Variable orifice tubes are also available, but they have not been shown to be worth the money.

97-10-05 does recommend +4oz of oil, but 97-15-05 specifies 7oz for '94-95 trucks & 11oz for '96, so I'd use about 10oz total.

AFAIK, only R-134a has passed the SNAP requirements for retrofitting into mobile A/C systems, and Ford advises against any other. I expect any supplier of a new/reman compressor will also stipulate R-134a for warranty.


It's actually PAG-46 that Ford requires. There is no PAG-47; just -100, -150, & -200.