What gas is inside my aircon? R12 or R134

[S2central.net]

When I said evacuate the system - I did NOT mean purge it to atmosphere by opening a service port - I meant have it professionally evacuated !

[johne]

Its only an offense if you knowingly vent the gas to atmosphere, ie crack a pipe off without evacuating or fill a car with a known leak.

R12 gas molecules are larger than 134a hence why it can leak. If all the seals are good in parts like compressor etc then they dont leak, the rubber pipes dont ever leak from being porous. Have converted loads and loads of vehicles and only had issues with leaks on 2, which were fixed with new seals.

+ the remains of the mineral oil used with R12 helps to seal the original rubber pipes so anyone with an R12 system shouldn't be put off from moving to R134a without changing everything.

John

[s2driveruk]

as my system was leaking with an RS24 drop in (oem system was R12), when i put it back together soon, does it make sense to just swap the remaining compressor oil to an R134a compatible version and refil with that instead? When the system was running last year with rs24, its was working great and the guy who filled it said that its marginally better in terms of overal cooling than an r134a gas.

Thoughts?

[johne]

Put the system back together, treat yourself to a new receiver/dryer from GSF (around £35 iirc) and then go and have the system vacummed out which will remove any of the old oil and refilled with R134 & the appropriate PAG or POE oil.

R134 isn't as efficient as the older gasses but I doubt you'll notice the difference when you've got a properly filled system on R134. Certainly mine works fine on R134.

R134 makes life easier as it's cheaper (?) and easier to find if you want to do a top-up yourself.

John

[s2driveruk]

thanks John, I bought and rec/drier yesterday from GSF so there is no physical port on the compressor to drain oil from, you just evac it before a refil....?

Cheers

[johne]

You can take the compressor off & turn it on its end to drain out but most of the oil will be in the receiver drier and the rest will be vacuumed out so I'd leave it.

John

[CoCaine]

Hi guys.

I have a 1991 3B.The aircon rad that was on the car broked up.I had a hole in it.
Now I have a good rad in place and want to refill with gas.
It seems that I can't find R12 gas here.
What do I need to do for refilling with R134a gas?
Remove the oil from the compressor,put a R134a oil and then refill with R134a gas?
Because I had that hole in the rad I think that there is no R12 gas left in the installation,am I right?

Cheers.

[s2driveruk]

yes, all the r12 will have long gone.

change the oil and refill with R134a, job done I would get a specialist a/c company to vacuum the system to check it is airtight and this will remove most of the oil anyway (i asked a similar question a while back) then refill with the correct PAg oil and away you go .

[johne]

Can be PAG or POE oil with the R134a. I've read that POE oil is more tolerent of other oil residuals (R12 systems used a mineral oil for lubrication) and is normally the one included in the R12 to R134a conversion kits.

OE fill for R134a systems is PAG. Most of the modern regass equipments meter it in automatically and I guess most operators won't know if it's POE or PAG they're adding

I've got POE in my system.

John

[s2driveruk]

good to know John, will have a looksy for some POE when i gas mine up in a week or so

[Skull]

the sticker specifying the gas is on the bottom of the drier.

i have the R12 system, and have bought the R134a system seals. i hope they will fit...?

[johne]

i have the R12 system, and have bought the R134a system seals. i hope they will fit...?

I've got a hybrid R12/R134a system and the green coloured R134a seals fitted throughout.

John

[Skull]

confirmed, the seals fit

[sailaz]

the sticker specifying the gas is on the bottom of the drier.

If somebody could tell part number for R134a sticker I would be very appreciated ( if such part number/sticker exists )