I am going to replace my evaporator, accumulator and orifice tub on my 97 Ram 1500 5.9. I have read where adding PAG oil is part of required when doing something like this and adding too little as well as too much can cause problems. I may be over thinking this but.....

1) Will charging with freon which contains an oil additive be enough?
2) Both?
3) One and not the other and vice versa?

Thanks,
Axtell

 

You can get the service manual for your truck from here. That will tell you how much you need in there. I prefer just to add the oil separate, that way, I KNOW how much is in the system.

 

Since you're not replacing the compressor (where a fair amount of the oil sits when the system isn't running), its kind of a crap shoot. I suspect that you'll be fine, but check the manual to be sure.

 

The oil is in suspension in the refrigerant when the system is running. When it isn't, it will settle out wherever it happens to be. When you vacuum the system down, it tends to remove most of the oil.....

 

Actually it sits in the bottom of the receiver/dryer, and any time you replace a ac component it's a bit of a guessing game to add the amount of oil that is in it because it gets spread out over the entire system.

 

Much appreciated for the quick responses and especially the service manual. Thanks again - Axtell

REFRIGERANT CHARGE CAPACITY (From 1996-97 Dodge Ram Service Manual)
The R-134a system charge capacity Is 0.9 kg (32
ozs.).

Refrigerant oil must be added when a accumulator, evaporator, or condenser are replaced. Refer to the Refrigerant Oil Capacities chart (Fig. 11). When a compressor is replaced, the oil must be drained from the old compressor and measured. Drain all the oil from the new compressor, then fill the new compressor with the same amount of oil that was drained out of the old compressor.

Component ml o z
A/C System 230 7.75
Accumulator 120 4
Condenser 30 1
Evaporator Coil 60 2
Compressor (see Oil Level Check)
J9524-6

 

I’m in the process of replacing the compressor as well. The service manual calls for measuring the amount of oil from the old compressor then measuring the amount from the new compressor. Once this is determined then you adjust the amount going back in the new compressor based on what came out of the old one. Problem is only 1 ounce came out of the old compressor (Sanden OEM). 5 oz came out of the new one. I find it hard to believe I am supposed to put back only 1 oz back in the new one. The accumulator and evaporator has already been replaced. The AC system was all original with 460,000+ miles on it.

Should I just add 1.75 oz during charge to top off the system?

Compressor 5 oz
Condenser 1 oz
Balance 1.75 oz
Total 7.75 oz = System 7.75 oz.

 

Has the system been refilled since the other parts were replaced?

 

No. It has not been refilled.

 

Is there any oil at all in the system? If all the parts are new, and you haven't added any oil to anything, then the system needs to full amount. If you have indeed added oil in the indicated amounts to the other parts, and the system hasn't ran/been charged, then the compressor should get its full five ounces.