Some AC questions

[geno8769]

My AC has 0 pressure in it. It sat for 5 years after Katrina and I am slowly bringing it back from the dead. It is now getting hot here in South Louisiana, so I want to get the air working.

I plan to change all of the O rings, and put a vacuum on the system. I will probably change the receiver dryer as well.

Could someone tell me the capacity of the system when I convert to R134A, what type of oil I should use, and what flush?

Thanks for any input and insight.

Have a great day.

 

[franklin2]

Simple answer; Go to walmart or the local parts store and get a r134a conversion kit, and follow the instructions. It will work fine.
Now you can sit here and read all the complicated and long replies about how you have to change this and change that, spend all kinds of money, or don't do it because it won't cool good enough and you should keep the r12. Don't knock it till you try it, it has worked for me numerous times on numerous vehicles.

 

[rhkcommander]

Didn't notice u said convert dso what I said below won't be 100%...
get some seals for r134a flush the system, r134a and oil. Same capacity roughly and measure the oil that comes out from the dryer and compressor, flush it good. After proper seals and flush and such you should be good

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Should be sticker under the hood with the amount you need. if flushing you can choose the oil, PAG most likely. Some refrigerant cans are charged with oil. Flush it and seal the system after. Moisture mixing with the oil is bad, and the same for desiccants in the receiver dryer...

Make sure to keep the caps on the dryer until right when your ready to install it too. And you will want a new one and flush if it's been sitting so long

Sorry I don't have any #s for you, my truck doesn't have ac yet...

 

[DragRag]

You can also charge the system to a suction pressure. I generally charge to a suction pressure between 38 and 40 psi.

 

[typ4]

^^^ what he said, also get a variable orifice tube for maximum effieceincy of the 134, I did mine years ago and it work great, and a new drier is a good plan.

 

[pybyr]

My AC has 0 pressure in it. It sat for 5 years after Katrina and I am slowly bringing it back from the dead. It is now getting hot here in South Louisiana, so I want to get the air working.

I plan to change all of the O rings, and put a vacuum on the system. I will probably change the receiver dryer as well.

Could someone tell me the capacity of the system when I convert to R134A, what type of oil I should use, and what flush?

Thanks for any input and insight.

Have a great day.

If anyone has a list of the locations and sizes of the o-rings- as well as part numbers or appropriate material type, I'd be _very_ interested, so that I can get all the parts on hand before opening up my system to replace the ones in my truck.

 

[icanfixall]

The above is really close on all accounts... One thing about the vacuuming down the system. You will need the ac gauge setup for that plus the vacuum pump... Don't have the expensive pump.... Build your own... Find a refrigerater thats not working... Remove the black compresser. Be careful removing it because of the possible pressure that may still be in the system... Usually its all leaked out by the time these stop working. Just solder on the correct fittings to the suction and discharge line and your ready to pull vacuum or pump a small amount of pressure... These compressers work best drawing a suction... Any frig or cold water fountain will have the same compressers. Look for the actual vacuum pumps on ebay.... They are very expensive at around $700.00.... Any frig repair shop willl sell you a compresser for around $20.00..... Please wear a full face shield when working around this freon... Any of it getting in your eyes and your blinded.... The R12 system was not designed for R134 but it does work..... Sometimes not as well as the R12 because of the smaller evap condenser up front.... My truck requires 3 lbs of R12. I run the low side pressure at around 40 to 50 lbs... 134 is a higher pressure system but I can't really tell you how high it is because I don't deal with it that much.... I use mostly the R12 because thats what my trucks use.... I have around 35 lbs of the R12 in the 1 lb cans I bought over the years on ebay.... You need a license for the stuff in that size cans too but not for the 30 lb containers as I recall... funny how that works...

 

[RLDSL]

35.2oz of R134a 10oz pag46 after flushing the system. You can do it without flushing the system and it won't really harm anything,R134a will not absorb R12 mineral oil so it will just find a low spot in the system and sit there...BUT it will use up system capacity and give you strange pressure readings. Best to flush the system and use a fresh accumulator. In your climate a variable orifice valve is a very good idea, along with an electric pusher fan rigged to come on with the compressor for better performance at low speed , it will keep the head pressures down and now only keep the cab cooler but make your compressor last longer. as far as orings, just get a big ford assortment pack and you will be good to go, about 8 bucks and it will have the most widely used HBNR orings for your year range ford get a bottle of Nylog to lubricate the orings for installation, or if you have an old can of r12 mineral oil, use that, but do not use the Pag oil to lube the orings, the stuff dries out orings and will cause them to leak. If you lube your orings with the pag oil your system will leak like a sieve .
If you need a hand with any of that and feel like a trip one state up, I've got all the goodies to do anything on an AC system.

 

[geno8769]

Thanks for all of the great info! I am sure I will have some more questions as I think about it!

 

[DragRag]

Gary, You do need the license for R12 in the 30lb can. You need it for any CFC or HCFC in any quantity actually. I still don't use R12 or R134a guys, for the older trucks I use commercial R12 replacements Like R409A or MP39. You can't buy those though without the license, it acts and works much closer to R12 then R134A any day. They are blends though, and must be charged in liquid for only. yes I know some of you are anti about them for worry of some other yea-hoo contaminating there equipment, but no one works on my a/c stuff but me. And, standard practice is to mark the system with a sticker stating the type of refrigerant that is in there. If a commercial refer guy can do, and automotive guy can mark his equipment properly to. I can tell you the R12 drop in replacements like R409A, MP39, MP66, Freez12 and the like work great and are easy for me since i have the stuff on hand anyway. This type of stuff is not really for the inexperience to handle, and may be cost prohibitive to use unless you use it in the quantities that I do.

 

[geno8769]

One other thing, can I change the evaporator core from the engine compartment? If so is there anything I need to watch for while doing it?

Thanks.

 

[RLDSL]

Gary, You do need the license for R12 in the 30lb can. You need it for any CFC or HCFC in any quantity actually. I still don't use R12 or R134a guys, for the older trucks I use commercial R12 replacements Like R409A or MP39. You can't buy those though without the license, it acts and works much closer to R12 then R134A any day. They are blends though, and must be charged in liquid for only. yes I know some of you are anti about them for worry of some other yea-hoo contaminating there equipment, but no one works on my a/c stuff but me. And, standard practice is to mark the system with a sticker stating the type of refrigerant that is in there. If a commercial refer guy can do, and automotive guy can mark his equipment properly to. I can tell you the R12 drop in replacements like R409A, MP39, MP66, Freez12 and the like work great and are easy for me since i have the stuff on hand anyway. This type of stuff is not really for the inexperience to handle, and may be cost prohibitive to use unless you use it in the quantities that I do.

I've got NO problem with you if you actually bother to mark it with an appropriate sticker. Every AC tech looks for the things even if you sell a vehicle, a tech can visually identify the refrigerant and evacuate to his trash receptical.No harm no foul. (There;s a disposal fee, but that goes through to the customer) Problem I have is with the DIYers who put that stuff in with r134a or r12 fittings and no markings whatsoever, which is 99.9% of the people who use that stuff., but that stuff really is not for diyers. It's not a practical option for someone who might have to have someone else fix the system down the road

 

[RLDSL]

One other thing, can I change the evaporator core from the engine compartment? If so is there anything I need to watch for while doing it?

Thanks.

All but one or two bolts that you have to pull teh carpet back in teh footwell on teh passenger side ( I think it is only one at the bottom) to remove teh cover and yes, the evaporator can be replaced from the engine compartment. It will be messy, buy you will need to seal the housing halves together. If you don't happen to have some of that mastic tape you will need to use some silicone and make a horrible mess trying to get it together, you may need to glob some extra on where you knock some off getting the outer half in place.
For better ac performance, get some of that insulation that is 1/4" foam with foil both sides and insulate the housing including the fan area to isolate it from the engine heat

 

[icanfixall]

Drag... Yes I do have the license to buy the r12 and install it. I really didn't recall about buying the 30 lb containers without the license. I remember reading something on the ebay sales stating no license was needed if you bought X amount and said it was for another purpose... Can't recall what it was these days..... About installing a "mixed bag" of refrigerants in the same system... As long as you lable it fine but most shops will turn you away if they check it and find its "contaminated" with other freon... Some fly by nite shops were using propane as freon... It really workd great too but the dander of an exploaion is there... I remember lots of differant freons available but never used any but R12... I have enought of it to last longer then me...


This is what I found about the license....
http://cgi.ebay.com/ebaymotors/30-l...r_Truck_Parts_Accessories&hash=item5d2c001ff1

 

[DragRag]

Gary, I am not sure what the law is in Canada, but here in the USA it doesn't matter what you are doing with it, and CFC or HCFC requires an epa license to purchase for sure without a doubt 100%. That is bad info if you want to buy it here in this country. EPA likes there fines so buyer beware. I copied and pasted there statement so everyone could read it, be very careful of that it will get you popped and him for selling it on the U.S. market to and unlicensed buyer. I could care less myself who buy sit, but just be careful of you decide to do that.



There quote, not miner!----You do not have to be a certified technician to buy this Freon, but if you are not a certified technician, you must provide a statement in writing (typed, scanned and e-mailed to us or may be faxed) that you are purchasing for resale only BEFORE payment is made and before pick-up and or shipped.