jeremy175

I'm in the process of converting my 88' Cherokee from r12 to r134, my question is how much ester oil do I need to add? I was told to change to accumulator out when converting. Anybody else got any more suggestions on converting?

BestDell18

All you have to do is vacumm out your system. Put r134 compressor oil in it, and change the fittings. Then you can fill it up and feel the fresh cold air.

4.3L XJ

Yes, you should change out your accumulator, also known as a filter drier. You can buy the oil in small containers, about a pint. It seems to me it takes less than that. I would check with an AC shop.

Firestorm500

1. Recover R12.

2. Drain and refill oil in compressor. Check specifications for proper amount. Could be around 11 oz.

3. Replace filter-dryer and orifice.

4. Change/adapt fittings.

5. Vaccum and recharge system.

6. The R134A will run 1-5 degrees warmer than R-12. It will leak out sooner requiring more frequent recharges. If R-12 is available, and everything else in your system is OK, put R-12 back into it.

SeriousOffroad

No, the Filter-Drier is in the Accumulator, they are two different components with different jobs. The accumulator holds liquid refrigerant and allows only refrigerant in a vapor state to be drawn back to the compressor. The Filter drier catches particulates and the Drier is a molecular sieve that traps and holds moisture.

I charge $120 per pound of R-12 with a 30 pound minimum...haven't sold any in 10 years. R-134A is a much better option.

There's no need to change or adapt any of the fittings on the Jeep.

Flushing the system with an approved cleaner is a good idea, as is replacing the Accumulator/Filter-Drier.

jeremy175

I can get the oil in a 3 oz can or 11 oz can. So should I use the 11 oz can of oil? I've already changed the accumulator out and installed the correct fittings. How long should I pull a vacuum for and what should my pressure be when I charge it up?

Abovetimberline

You should pull a vacuum and hold with pump off for about 30 min,the normal high and low are 30lbs low,215 high. I used one of the larger cans of oil when I charged mine,11oz sounds normal.

jeremy175

Alright buddy I appreciate it

brucebo

Check out this thread, starting at #10.

https://www.cherokeeforum.com/f2/r12-134-a-19231/

jeremy175

How many can of the refrigerant should I need? And which oil chill do I need? I see there is a 4 oz can and a 8 oz bottle.

SeriousOffroad

Typically 10-15% less than the amount of R12 shown on the dataplate under the hood.

Firestorm500

I was talking about going to an A/C Certified shop for the R-12 fill. Unless the OP is certified, he should not be doing this himself. (The mechanical part is OK).