I need to recharge the coolant on my daughters 1989 240 DL. According to the sticker on the fender it was converted at the factory to R134A.

The only low pressure fitting that I can find is directly on the compressor. The fitting does not have outside threads and has the raised "band" on a smooth barrel as it should be for R134A. However, the fitting my coolant gauge does not appear to be deep enough to engage the ridge and it feels like the diameter is off as well.

Did Volvo use non-standard fittings during the transition period to R134A?

 

First things first. The "factory" would not have done the conversion. Only the 93 model came w/ R134a, earlier models all made it to the states w/ R12. Perhaps a dealer did it...but it wasn't done at Goteberg. Many 240's (I have an 89 too) live their entire life without the high pressure side of the compressor accessed. So...many conversions are done with only the low side fitting affixed as the high side is Hell to get to. Be advised, the high side and low side fittings are different sizes and lengths to keep people from blowing things up. The high side fitting is larger, the low side smaller. The R12 Shraeder valves were the same diameter so it is quite possible either someone used the wrong size fitting or you're using the wrong hose coupling. I believe further examination may be in order before you lose an appendage...just sayin' YRMV.

 

The low pressure fitting is on the compressor. The large hose coming from the firewall to the compressor is the low side. Make sure that you are hooking up the low side fitting.

Beware that the cooling capacity of these cars is terrible. The systems are too small for hot US climates.