I am in the process of changing from R12 to R134a.

I have all necessary fittings, hoses, etc, and once I am sure of where the adapter goes, will place it and apply vacuum for 30 minutes before charging with 134a.

What I am not sure of is the location of the low pressure side fitting on the rear of the Diesel-Kiki AC compressor that is on the vehicle.

In the process of having the remaining R12 sucked out, it seems that the two fittings on the rear of the compressor are different size. The fitting on the service guage did not want to thread onto the upper left fitting on the back of the compressor. Grant you it is hard to get in there but even aligned it did not want to turn more than 1/2 turn then stopped.

The lower right fitting allowed the R12 service fitting to spin on without problem. The R12 was pulled out through that port.

I am concerned that the R134a adapter will not fit the present adapter at the upper left of the back of the compressor which being next to the large hose coming from the evaporator should be the low side port. This seems to be the larger of the two fittings and unless I just had too hard of a time aligning the threads, I am concerned the port will not accept the R134a charging fitting.

Will someone with familiarity with this process please provide me with some insight?

Thanks,

PS It hit 100 with an index of 112 about noon today so I would like to get this functioning as soon as possible.

Well, the low is the driver's side port but if you have not installed the R134a fittings onto the old ones, I am not sure what gauge/pump/fitting combo you are using. Fittings for 134a differ and the gauges correspond to the fittngs. Furthermore, the high and low fittings for 134 differ. Watch that teh schraders make sence when you add the fittings. Some require you gut the old schrader while some just activate the inner valve when the fitting valve is depressed. I'd go more than a half hour too. Change or add ester oil.

Fittings are from Interdynamics. They are supposed to screw over the existing valves on the back of the compressor. They do fit the appropriate 134a fittings on the end of the Snap On 134a AC guage and service unit.

The 134a high pressure side fitting is the same thread as the R12 recovery hose fitting used, which only fit the passenger side fitting of the compressor which threw me off. It was supposed to be the low side of the R12 guage set.

The 134a low side fitting has a noticably larger thread diameter which would indicate that it will indeed fit the drivers side port on the rear of the compressor.

I'll find out tommorrow when I attempt to figure out how to tighten the fitting down with that hose "thing" on the back of the compressor in the way. I guess if needed I can remove that hose "thing" to gain clearance since I'll have to evacuate the entire system anyway.

Thanks for the longer than 30 minutes vaccuum draw tip. As I was doing more research I came across a few statements that indicated if temps were above 80 degrees add 20 minutes to the total vaccuum time. I'll be close to that temp in the shop where I work so the longer the better.

Thanks, I hope to be a "cooler" driver after tommorrow wihtout Pimping my Ride