AC Conversion

[seacow]

I would like to swap my ac over to R134A and seeing how my feron has leaked out and AC doesnt even work anymore figure it shouldn't be to hard. However, not sure if i need to replace my compressor?? Any tests to see if it is working right?? Also what is average cost and parts need to do the conversion?? Any place i can rent or use a evac to check for leaks?? anyone in the southeast Idaho area??

 

[jperecko]

There are a couple parts that HAVE to be changed out when you convert to R134 as if it mixes with any R12 or residue it will cause the "black death" and will require you to change ALL your AC parts. I think the dryer is one of the parts that needs to be swapped but there are more but I do not think the compressor is one of them. You can pick up or borrow a vacuum pump to check for leaks but seeing as your R12 leaked out, you have leaks. Start with a basic seal kit and change the necessary parts then see if it holds vacuum.

This is another one of those pretty general auto mechanic things that you might want to get help from somebody who knows locally instead of tackling something you know nothing about.

 

[argve]

Around here you can "borrow" a vacuum pump and gauges from Autozone under their loan a tool program.

Now for this "Black Death" thing... Never experienced it guess I was just lucky. Have done many of the system converts and none of them died. What I did was picked up one of the convert kits from the autoparts store that had the conversion oil and refrig in the box along with add on fittings that screwed on the old R12 style fittings.

I would vacuum the system down then install the oil, then start filling with the cans of R134a. I picked up a Haynes Manual on HVAC systems for vehicles and in my copy it said that when they started writing the manual that it was recommended to swap everything then by the time the book actually went to print it had changed like two times in that less and less was recommended for change over so they basically said at this time it was recommened to swap over the drier and oriface tubes... I didn't swap over anything and it worked just fine. All I did was only fill to like 80% volume - which if you notice the cans of R134a contain less than the old cans of R12 do (volume)....

Not discounting the "black death" thing but I will hold my hand up and say I have never seen it on any of the vehicles I owned..... Don't maybe I was lucky... but I've never been lucky on anything before so it would be first for me...

 

[RLDSL]

Very least you will need a gauge set, you can rent a vacuum pump at a rental yard, since it's leaked out, hook up the gauge set and vacuum it down and see if it holds a vacuum for 30 minutes, if not, you have a leak big enough that you need to fix before filling, replace all teh orings and try again( use nylog or r12 mineral oil to lube the orings, , do not use pag or ester oil to lube the orings, it dries them out and you WILL get future leaks)
If after replacing all the orings, you still get leaks and can't hold a vacuum, the compressor seals are shot and you need a new compressor. do not bother with repainted...oops, I mean rebuilt, get a new one, they usually cost less anyway

You will need a new accumulator, orifice tube( a variable orifice valve will give you a colder ac system) a can of PAG 46 oil 10 oz for the system

If the old compressor has not siezed up and failed, then removal of al the old r12 oil is not completely needed. r134a does not absorbe mineral oil so it just settles in low spots, so just blowing the majority of it out is fine, but if there are signs of contamination( grey residue in the lines) then you must remove all the parts and get a can of ac flush and run it through and flush all the componants thoroughlly, lay the condenser flat to flush, and it is wise to get a filter for the suction side line and the pressure side line and have them installed in the hoses to prevent your new compressor from failing ( in fact filter installation is mandatory for warranty coverage in most cases )
Holler if you get stuck

 

[FordGuy100]

I would like to get my AC recharged, though I think recharging R12 is expensive as heck

 

[RLDSL]

I would like to get my AC recharged, though I think recharging R12 is expensive as heck

If you can wait till you get down this way, I'm certified for the stuff so we'd be able to get you fixed up a little more reasonably. Of course, that wouldnt do you much good heading cross country . It still costs a bundle a can, but you'd save the silly high shop rate, Or i could walk you through some mods to make the thing so cold on r134a that you wouldn't miss the r12

 

[jtate]

Very least you will need a gauge set, you can rent a vacuum pump at a rental yard, since it's leaked out, hook up the gauge set and vacuum it down and see if it holds a vacuum for 30 minutes, if not, you have a leak big enough that you need to fix before filling, replace all teh orings and try again( use nylog or r12 mineral oil to lube the orings, , do not use pag or ester oil to lube the orings, it dries them out and you WILL get future leaks)
If after replacing all the orings, you still get leaks and can't hold a vacuum, the compressor seals are shot and you need a new compressor. do not bother with repainted...oops, I mean rebuilt, get a new one, they usually cost less anyway

You will need a new accumulator, orifice tube( a variable orifice valve will give you a colder ac system) a can of PAG 46 oil 10 oz for the system

If the old compressor has not siezed up and failed, then removal of al the old r12 oil is not completely needed. r134a does not absorbe mineral oil so it just settles in low spots, so just blowing the majority of it out is fine, but if there are signs of contamination( grey residue in the lines) then you must remove all the parts and get a can of ac flush and run it through and flush all the componants thoroughlly, lay the condenser flat to flush, and it is wise to get a filter for the suction side line and the pressure side line and have them installed in the hoses to prevent your new compressor from failing ( in fact filter installation is mandatory for warranty coverage in most cases )
Holler if you get stuck

x2 on what rldsl said. when you change the orfice tube it will most of the time give you a pretty good idea of what was happening with the system. if there is any signs of failure going on in the system this is where your going to see it. the orfice tube is not just a orfice but a slight filter as well it will accumulate aluminum shaving sometimes to the point that the ac just doesnt put out like it used to. rldsl methods are pretty straight forward as what i practise .

 

[The Warden]

Or i could walk you through some mods to make the thing so cold on r134a that you wouldn't miss the r12

Pray do tell you have my attention now...my goal is to get ice cubes coming out of my a/c vents

Thanks

 

[lotzagoodstuff]

Don't be affraid of converting this yourself. The "Black Death" scenario is genuine but is usually caused by incompatible oils when switching to other than R12, usually the seals or hose inner tubes breaking down and plugging/damaging a/c components. I have changed over at least a dozen vehicles with no problems, but none of them were all that bad to start with. You will not get as cold with 134A as you will with R12, but these older trucks have well sized systems, not like the typical newer passenger cars, so it will be cold enough to keep you comfortable.

Change/inspect the small orifice filter, have a look at your compressor and see if it still turns and makes "nice compressor sounds". If you haven't opened up the a/c system, you'll probably be alright. The key is getting it really clean and pulling a vacuum down on it to get all the air and more importantly moisture, out of the system. I am a big fan of putting a small pressure (like 10-20 psi) of nitrogen on the system and using soapy water to look for external leaks at all the joints, but a bad leak will show up with oil at the leak. Take your time and ask lots of questions along the way and you'll avoid spending any unnecessary monies.

Good luck

 

[FordGuy100]

If you can wait till you get down this way, I'm certified for the stuff so we'd be able to get you fixed up a little more reasonably. Of course, that wouldnt do you much good heading cross country . It still costs a bundle a can, but you'd save the silly high shop rate, Or i could walk you through some mods to make the thing so cold on r134a that you wouldn't miss the r12

I will have to take you up on that . My ac is ok, but it used to be ice cold. The other day it was pushing 95* and I turned it on, and it was like, ok, when are you going to get colder. It helped, but it needs to be freezing

 

[JwS]

I just did mine and it is working great, I pulled everything out, flushed out each hose and the evap and condensor, new compressor and orifice tube, put it back in and sucked it down good, then filled it. all in all it cost me about $300 total I guess. I think pulling the evap to get a good flush out is key, and check the I.D.s of all the fittings to make sure they are smooth. Ford has a Service bulletin that recommends honing them out with a little scotchbrite on a drill, which I did to remove some little scratches.
JwS

 

[seacow]

OKAY, I am staring to get this. One question though, how do i flush the system?? Just pull the system apart and blow compressed air through them?? How bout the compressor? I really dont wanna have to take that damm thing out?? But it has been 2 years since it has had working ac so iam sure the o rings are shot at a minimum??

 

[subliminal]

you can buy a flush and run it through with compressed air. also exter oil might be better than the pag as far as being compatible with the mineral oil that r12 uses. thats the main issue. if you do flush it out completely use pag oil if you leave some of teh old oil in the system its best to use ester.

 

[seacow]

What lines should i disconnect to flush it and where should blow the comppressed air into?? Should the truck be running with ac on when i flush it< or will blowing the oil out with it running seize the comressor?? right now compressior cycles 3 sec on and 5 secs off at idle??

 

[mech140]

I can help anyone down my way with these issues and all it will cost you is what coolant (r-134)we use.....This is what the brotherhood is about, Right......