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The (hopefully) official R134a conversion thread

imiceman44 said:
I like having the A/C seperate so if you seize a compressor, you don't lose everything.
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That's a great point, and probably why my '05 Yukon has a separate belt for the A/C compressor. If it fails, I can still keep going down the road.

There is also an A/C bypass pulley w/ bracket available at most auto parts stores which wouldn't be a bad "just in case" item for those of us stuck w/ a serp setup.

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I drive a big rig Freightliner and a few months ago I stopped for a break and I look down and see a belt dangling, I open the hood quick and see my A/C belt hanging, the rest still all fine and dandy, I almost crapped my pants but I was so glad they seperate them that way.
They are both ribbed but the serpentine takes care of all the engine parts and the other is just A/C.
ALl my other trucks are V belts 2 or 3 belts each and one has 4 belts.
I want to see if I can con convert them to Ribbed for better friciton control.
clandr1 said:
That's a great point, and probably why my '05 Yukon has a separate belt for the A/C compressor. If it fails, I can still keep going down the road.

There is also an A/C bypass pulley w/ bracket available at most auto parts stores which wouldn't be a bad "just in case" item for those of us stuck w/ a serp setup.



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imiceman44 said:
I don't know about too much to convert, I got the conversion kit which is 2 adapters for low pressure and high pressure ports and the cans containing the r134 and oil and additive in the same can.
I vacuumed for a few minutes then charged it till I got the right pressure.
Can't get easier than that.
Never changed anything either, unless there was something wrong, bad parts etc...
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This is the format I used but I also used a can of startup lubricant.
 
Ribbed for better friciton
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Really? Did you really type that???

I had an idler pulley bearing go bad on my M-Class, and it shut down everything. Made me wish for separate belts.

I once drove some model Ford pickup, that I think had a separate belt for everything.
I know the alternator belt broke, and the only reason I knew was because it stopped charging.
If I were building a vehicle for max reliability, such as military use, I think I would try to have individual belts for as many uses as possible.
Of course, for max, I might have a flat serpentine for just the water pump and fan, with a backup electric fan and water pump in case the belt failed under fire and it was move or die.

Of course, you cannot anticipate everything. My Torino had separate belts. I punched it one time to pass a car, and the engine went dead.
No sputter, no funny noise, no warning, nothing.
Coasted to the side of the highway. Opened the hood and discovered the air conditioner fan belt broken and laying across the engine.

Trouble was, that was all it drove. Breaking that should not bother the engine. Kept looking, and saw that when it broke, the end whipped around, hit and unplugged the connector for the ignition module.
Didn't hurt it at all. I just plugged it back in and drove to get a new belt.

You just never know.....
 
Fordum said:
Really? Did you really type that???

I had an idler pulley bearing go bad on my M-Class, and it shut down everything. Made me wish for separate belts.

I once drove some model Ford pickup, that I think had a separate belt for everything.
I know the alternator belt broke, and the only reason I knew was because it stopped charging.
If I were building a vehicle for max reliability, such as military use, I think I would try to have individual belts for as many uses as possible.
Of course, for max, I might have a flat serpentine for just the water pump and fan, with a backup electric fan and water pump in case the belt failed under fire and it was move or die.

Of course, you cannot anticipate everything. My Torino had separate belts. I punched it one time to pass a car, and the engine went dead.
No sputter, no funny noise, no warning, nothing.
Coasted to the side of the highway. Opened the hood and discovered the air conditioner fan belt broken and laying across the engine.

Trouble was, that was all it drove. Breaking that should not bother the engine. Kept looking, and saw that when it broke, the end whipped around, hit and unplugged the connector for the ignition module.
Didn't hurt it at all. I just plugged it back in and drove to get a new belt.

You just never know.....
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I guess you really didn't read my whole thread?
I said I want ribbed belts, not serpentine which means all in one.
I like individual belts but the ribbed belts are better gripping, more area for better traction if you will.
 
imiceman44 said:
:doah:
I just figured it out
Well I didn't have a dirty mind, I wasn't in the pen
Sheesh
:rolleyes:
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It worries me sometimes that I do see that kind of stuff.......

But then I miss one completely and I figure I'm totally beyond redemption....
 
Fordum said:
It worries me sometimes that I do see that kind of stuff.......

But then I miss one completely and I figure I'm totally beyond redemption....
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Well I was the master of catching these things, and I did that trilingual, so if you said something that meant something like that in another language I would be :whistle:
In our family we knew 3 languages so it was fun for me to keep everyone on their toes.
Now I am here and all the ones that I see here don't do me any good because no one understands all the languages I know.
I just added a couple of them with my marriage and the new greek church I go to.
But on here I started turning my radar off, and that let you get me:doah:
I'll get you back.:thumb:
 
I was never all that up on other languages, although for some reason I picked up some Latin...

But, I was good at obscure references.

For instance, I often told girls they were spathic. By the time they figured it out, I was out of slapping distance.

Don't know if I could get away with it now since most girls have internet access on their phones........
 
The compressor was delivered yesterday by UPS. I now have everything I need component wise. Next up is making sure I have access to a flush kit and vacuum kit. Any recommendations? I heard Autozone rents them, maybe I should check there unless anyone has any better ideas.
 
So it seems my buddy has a vacuum pump and gauges, but what should I do for a flush? Rent a kit, or is there a way to do it without special equipment?

We're planning on doing this Monday afternoon, so replies by Sunday are most welcome...
 
All i did when i did mine was use that special ac solvent stuff and just poured it in one line and blew compressed air through it to make it come out the other side.
 
y5mgisi said:
All i did when i did mine was use that special ac solvent stuff and just poured it in one line and blew compressed air through it to make it come out the other side.
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Gotcha. I'm assuming the correct process would be remove components I'm replacing, flush system, put recommended amounts of oil in the various replacement components, install, then put a vacuum on it. If it holds, fill with refrigerant and enjoy. If vacuum doesn't hold, put some uv leak tester in the system and identify areas that need attention.

Sound right?
 
Remember, unless the filter/dryer has come apart and filled the system with crud, or the compressor has grenaded internally, the worst thing in there is going to be moisture.
A vacuum by its self can only do so much. One you have pulled a vacuum on it and there is no more flow, any water molecules left in there are just going to stay there.
This is why in critical systems, they do what is known as breaking the vacuum.
You pull a vacuum, then "break" it with a dry gas.
Usually nitrogen.
Any moisture in there will mix with that gas, and get sucked out when you pull a vacuum on it again.

Back in the day, I just pulled a vacuum on the system, then hooked some Freon up to the high side and sucked it out the low side flushing out anything bad.

The reason I bring all this up, is because most air hoses have a large amount of moisture in them.
Often more than the surrounding air. So, use shop air with care.
 
Thanks for the input, I'll follow your recommendation of putting some freon (134?) through the high side and flushing it.

I'll check my factory service manual for recommended refrigerant and oil amounts. I read that you typically want to shoot for 80% of the R12 capacity when converting to R134.

Also, is it necessary to add oil to the system when using R134? I know my compressor came pre-oiled, and I'm assuming I'll still want to add oil to the drier and condenser per the factory specs, but want to make sure I'm not doing something that isn't necessary.
 
Well, according to federal law, you are not supposed to release any freon into the air......
And I'm sure no one ever does that........

As for the oil, everytime I have seen factory instructions about replacing components, the book always give amounts to add per unit. So much for a drier, so much for a condenser, that sort of thing.

The basic theory, is that a set amount of oil is put in when the unit is built, and it flows around the system collecting certain amounts in the different units.
So, when you replace a unit, it will have some oil in it, and you want to replace that amount so that the total oil in the system stays the same.

I have seen some people carefully pour the oil out of driers and things like that, measure it, and then add that much plus a small amount to allow for that coated the inside of the unit and did not pour out.

If you have to make a mistake, its probably better to have a small amount of oil too little than too much.
As long as the compressor stays oiled and a small mist coats the inside of the hoses to help prevent leaks, then there is enough in the system.

Too much oil will tend to block the flow of the freon, and stop up the orifice tube.
 
Don't forget, I did most of my refrigeration work back in the good old days. I flushed with freon because it was cheaper than nitrogen.
Never though a thing about reclaiming freon. I was working on a large water chiller one time that held exactly 50 pounds of freon 12. I dumped the full charge, replaced the expansion valve, and put in a 50 pound tank.


I should have checked my pressures, because it turned out the drier was stopping up too.
So, I dumped that 50 pounds, replaced the drier, and filed it up again.

Never even gave a thought to having dumped 100 pounds of freon to air. I think I was paying about .50 per pound.
 
Fordum, thanks for the tip on collecting the existing oil and measuring accordingly. I'll keep that in mind and if I'm unsure, I'll use less than what I think I need.



Today I picked up what I think will be the last of the items I'll need to get the system converted:
  • PAG 64 oil with UV dye 8oz (P46UV) $10.99 @ O'Reilly
  • Four 12oz cans of R134a (I took 80% of what the service manual recommends for R12 per recommendations online based on successful conversions) of which I will use approximately 42oz (R134a-12) $14.99 each can @ O'Reilly
  • A/C system flush 1QT (CQS11) $13.99 @ O'Reilly
  • R134a compressor cycling switch (36675) $18.99 @ O'Reilly
I was glad to see the R134 cycling switch for sale, because I'd heard that you needed to lower the target pressure for the compressor, and I wondered how I was going to do that until I started looking at A/C parts on O'Reilly's website.

At this point I have approximately $500 invested in the project. Hopefully Monday evening after I'm done it'll prove to be money well spent.
 
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