Air Conditioner Advice?

[oldcorollas]

sorry, i just assumed everyone had a vacuum system at home

[Dale]

Oldcorolla's, also the system needs to be evacuated. Some places will just remove and replace the gas, but when converting a vacuum pump needs to be used to suck all the old contents out.

For those who want to go cheap, bare minimum would be :

- Replace Drier
- Evacuate System
- Add New oil compatible with R134a

Evacuate (vacuum the system down) needs to be done regardless of what gas is going in.

Really all that needs to be done is a change of the oil, as a good vacuum should remove all moisture from the system.

If you want to save money that badly you could always get the fittings and fit them yourself (they just screw onto the existing R12 fittings), get a receiver drier and fit it yourself, drain oil out of the compressor and then take it in for a "regas" and oil (they normally add some oil with every regas anyway).

I'm pretty sure they vacuum out the old oil anyway, not drain it?

[Z2TT]

Evacuate (vacuum the system down) needs to be done regardless of what gas is going in.

Really all that needs to be done is a change of the oil, as a good vacuum should remove all moisture from the system.

If you want to save money that badly you could always get the fittings and fit them yourself (they just screw onto the existing R12 fittings), get a receiver drier and fit it yourself, drain oil out of the compressor and then take it in for a "regas" and oil (they normally add some oil with every regas anyway).

I'm pretty sure they vacuum out the old oil anyway, not drain it?

Yep is what I'm going to do, Most do vacuum it, unless it's some backyard mechanic.

I'm going to replace my Compressor and Reciever/Drier, however is it necessary to get the SAME Reciever/Drier for the specific car, or will any R/D do as long as it has the compatible desiccant with the gas I want to use?

[allencr]

Yep is what I'm going to do, Most do vacuum it, unless it's some backyard mechanic.

Yeah, you tell-'em!!
Changing the oil/flushing is a real bitch if you want to get everything 100% clean & free of the old oil, but even jobs that leave in nearly 50% of the old oil seem to operate just as well, so I can't say that the effort is worth it.

Why hasn't anyone written that the R12 hoses have to be replaced because they'll leak since the R134 molecules are smaller, or has that old wives tale finally bit the dust?

When R12 was cheap & not a threat to the planet, it was quicker/more convenient to fill it, dump it and fill it up again, then hearing 1/2 hour of vacuuming BUZZZZ.

[Z2TT]

Why hasn't anyone written that the R12 hoses have to be replaced because they'll leak since the R134 molecules are smaller, or has that old wives tale finally bit the dust?

I think the hoses wont matter, but its the seals/o-rings that you have to change to ones that are compatible with R134a and with the new oil. But In another thread, Cruzida says the original seals are fine with both gasses?

[wagonist]

I think the hoses wont matter, but its the seals/o-rings that you have to change to ones that are compatible with R134a and with the new oil. But In another thread, Cruzida says the original seals are fine with both gasses?

I wouldn't worry about the hoses. They are both gases, & the molecules are both very small anyway, just the R134a ones are relatively smaller.
It's news to me about the old seals being compatible with the new gas, but if the old ones have been in there, and you've got the time/patience/opportunity to change them yourself, it'd be worthwhile to limit any chance of the system failing. It's only $15 worth of parts, but a lot of labour (here's where the money is saved by DIY).
Most A/C places would be ok to evacuate the system, sell you the seals, let you take the car away, do the fitting & then bring the car back for gassing.
I would let them fit the receiver/dryer. It's only a 2 minute job & they shouldn't be exposed until just prior to the system being gassed.

[Z2TT]

I would let them fit the receiver/dryer. It's only a 2 minute job & they shouldn't be exposed until just prior to the system being gassed.

Why is that?

Would there be a problem if i fitted the R/D myself then took the Car for a re-gas in a day or two?

[wa5]

The reciever dryer is not supposed to be exposed to atmosphere/ moisture.

[oldcorollas]

dessicant.......

[Z2TT]

Ah thanks,

See thing is far too many places like to charge rip off prices for installing an item, I'd much rather put it in myself. Would a day of exposure to the atmosphere deplete the dessicant a lot?

Thanks.