Hi Again Forum. Its been awhile.

I have a 1992 F-350 crew cab and the A/C compressor needs to be replaced. If I change it I will also change out the receiver/dryer, and orfice tube. I have heard that if I convert it over to 134a I would have to Upsize my condenser and maybe put a electric fan on the front?? Is this true? And have any of yall heard of Freeze 12? and if so i would like some info on it. Should I do 134a or Freeze 12?
Thanks for your input..

 

Personally I'd stay away from the Freeze 12, it's a blend of couple r's, makes it difficult to get serviced should you need it at a later date. Besides R134 is actually one of the best r's out there for efficiency.

Make sure you flush everything, use compatible oil, Find out if compressor is shipped wet or dry and how much is in it, then add according to specs, spreading around system. once its together, turn compressor by hand several times to make sure cylinders are not full of oil when the clutch kicks in the first time. Also change the orfice.

Evac. Then evac some more. If you can't get it down to 29 take to someone who can. Make sure it holds for at least an hour before charging. Charge with pure r134, no oil or dye or laek stop additives. Volume should be apprx 82% of R12 spec. High side should not exceed 2.5 times ambient measured 6-8 inches in front of condensor. Doors open , blow on high an max ac setting.

As far as the fan is concerned, depends on how well your current set up is doing now, if you have gauge creep at the light, then you may want to addd the fan.

you'll also need to add a high pressure cut off switch if it's not already equipped. Ackits.com has one thats about 20 bucks, cheapest I could findit.

Good luck!

Dart

 

Dart,
Thanks for the input. As far as the flush goes? Is that something that comes in the conversion kit? i have no gauge creep, Im assuming you are talking about the temp? And, the orfice tube. Auto parts store list 3 different ones, Red Blue, or VOV. Do I just get the VOV? What does it matter if the compressor is shipped wet or dry?
Thanks for the input

 

I understand about the compressor now after rereading your post. How would I know if I have a High pressure switch? Where is or would that be located? Also, My rig calls for 44oz, I would only charge it to 82% with the 134a? Is that how I understood that... Thanks again for your help.

 

Hi pressure cut out, cuts off the system (via clutch) if pressures exceed set amount, law requires on a retrofit so no refridgerant is release to atmosphere.

The flush, no it doesent come with the kit, I use Mineral spirits foloowed by a blast of brake cleaner to remove left over oils.

Yes, 44oz x 82% should equal optimum charge.

VOV, Tim at ackits told me they showed no improvement on the systems he had done, I would go with the blue one, but you might want to check on the forum over at www.ackits.com

Kit, i wouldn't spend the money, Get a couple good adapters, good bottle of oil, and four cans of pure freon. 4x12 =48 so you're not going to use the last of the 4th one. Works out to about the same money as the "kit" and you get much better fittings. The ones in the kit just screw down over your current ones and are prone to leaks, good ones are made of brass and require valve core removal from the existing ones.

One thing I forgot to mention, if any of your lines have mufflers/filters built in, you may seriously want to consider replacing them, mufflers are almost immpossible to flush clean but hold junk from "dead" compressor waiting to introduce to new one, $30 dollar hose now or $200 commpressor plus freon oil ect next week.....

Again check www.ackits.com They have an excellent article about flushiing, excellent prices, and lots of Tech help. Rapid response to posts too.

Good Luck

I'm out of here for the next week

Dart

 

Dart,
Thanks again for all the helpful info and the time to write it down. I will checkout Ackits. I have heard to many people saying that the 134a has caused them problems and I just wanted some outside advice. Thanks again and I'll let you know how it goes.
Thank You.