i have a 1994 f150 4x2 6 cyl. i am putting a new a/c compressor in and it came with a bottle of pag oil. i have a bottle of refigerant oil that you put in like a regular r134 can. which one should i use? if i use the pag oil do i just put it in the manifold lines in the back of the compressor and how much? im doing this tonight so any help ASAP would be much apreciated

 

ok before you do any ac work do some research first i would use the one like the r134 can but lets go over the steps to ac repair.
1. reassemble parts.
2. pull a vacuum on the system with a vacuum pump until there is 27Hg vacuum on the system.
3. Turn off vacuum pump and let sit for 30 minutes. Come back and check if the vacuum is holding at 27 Hg this means you have no leaks.
4. attach the pag oil to manifold gauge set and let that get sucked into the system.
5. start vehicle and turn ac on max cool with windows down. attach your r134 can or 30 lb tank to manifold gauge set and fill system until compressor does not cycle.
6. check temp coming out of vents it should be at most 20* less than outside temp with windows open.

 

Your new compressor will need oil in it before installation to avoid a "dry start". Otherwise you may damage it before the oil travels thru the system and reaches it. You can pour the oil into the intake side and turn it through by hand to suck it in. I would turn it through by hand several revolutions after installing it and before cranking your engine as well.

 

^^what he said i forgot to mention that part in the instruction sorry its been a while

 

I don't remember being able to buy a dry compressor anymore, that is pretty old-school. The past 3-4 compressors I have bought have oil already in them.

PAG oil has kinda gone away, I think Ester oil is preferred for R134a now, isn't it?

 

TSB 97-10-5 says PAG oil.

 

X2 PAG is what you want for R-134a systems

 

Your replacing the compressor without replacing the accumulator / dryer? The compressor is the lion share of the money, the dryer is quite cheap and should be replaced as well, IMHO.

 

no i am replacing the accumalator as well. i bought a "kit" off of ebay from discount a/c parts (the seller) and it came with a compressor, accumalator, bottle of double capped pag oil, orifice tube, and all o-rings. seems like a pretty good kit and they had a lot of good feedback. and it was only 245 for everything. i but the oil in and cycled it by hand but i gotta say it was a bitch to do. unfortunetly i didnt pull a vacuum just put the r134 in and it was ice cold at first but today its only luke cold (if thats a word) and it sometimes stop blowing all together. my questions 1) could air in the line keep it from getting cold? the line coming out of the accumalator is getting cool/cold and the compressor is running just not as cold as it was last night when i first put it in. 2) could the plenum door be keeping the air from blowing? ive never had that problem the air always blew even when the a/c wasnt working. it would always just blow hot air.

sorry so long winded but you guys are so freaking helpful thanks again for all the help

p.s im almost done getting this sucker back on the road

 

You really should have pulled a vacuum and let it hold for a while to see if your system was void of any leaks and to remove any moisture and air that was in the system. Since your system is not cooling as well now I would suspicion you have a leak and have lost your refrigerant. The problem with the intermitant cooling may be vacuum related (leak) and allowing your blend door to close and shutting off your supply to he dash vents. You never mentioned the amount of refrigerant you installed but you need to probably start over with a vacuum and determine if there are leaks then charge it with the proper amount of refrigerant. You also need to do this with a set of quality guages so you can see pressures and really tell what is going on. If you do not own guages and a vacuum pump, Autozone has a loaner program where you can pay a deposit and get it back when you return the equipment.

A/C work is not rocket science but if you do it right the first time it will work properly for many years. Plus.....once you learn it, you can repair your friends and family's vehicles.

 

I think we should go back to the beginning and figure out what caused the OE compressor to fail.

Was the Orifice tube replaced?

Is the OE dryer defective?

And as mentioned, is the system free of leaks?

 

the orifice tube was replaced. the original issue with the a/c was that the freon would leak out in a matter of hours and the a/c would just blow hot air and the clutch would not engage (like a low pressure issue). a friend of mine used a "sniffer" and a mechanics microphone to both smell and listen for leaks but we couldnt find any so we assume the leak was probably a seal in the compressor. he put a set of gauges on it and it held vacuum while we were there working on it but by the next day, hot air and no clutch engagement. i replaced the orifice tube, accumalator, compressor. i did not pull a vaccuum when i refilled the r134 but now two days later the clutch still engages and its blowing cool air just not cold air. the accumulator is getting cool to the touch as well as the line coming out of it going across the rear upper firewall. so i am assuming i have air in the line. so that's where i am at. my wife drove the truck to school yesterday and said intermittently the air would stop blowing. it didn't matter if she was driving or stopped at a light. im gonna try to have my buddy bring his stuff gauges over and pull a vacuum on it and refill r134.

again sorry so long winded but im trying to get as much info out there as i can

thanks for the help

 

that is exactly what i would do pull a vac on it and let it sit for 2 hours and check to see if the vacuum has held up