Aircon recon/convert/recharge services

[OneCarefulOwner]

My Lexus has the older style r12 air conditioning gas, and it needs converting to the more modern r134 gas. Can anyone recommend a technician or company, preferably in (South) London, although I'll travel for good service - I enjoy driving the car, so it's certainly not a hardship!

[jimmyybob]

I think the connectors that are different as well. i think you can buy adapters for them and then when no one is looking vent all the old gas out fit the new connectors and take it for a normal re-gas.

[JPB]

....I enjoy driving the car, so it's certainly not a hardship!

Then save yourself the hassle of converting by having a lovely long trip over the Border to pretty much any Scottish aircon recharging place. R12 is still legal there other than for the DIY market but this, like so many other handy loopholes will probably catch up with English law soon enough.

[alabbasi]

For the most part, i would not recommend converting to R134, although you may be OK given that it rarely goes over 80 degrees F in the UK. If you decide to convert, at the bare minimum, you will need to:
1) flush the condenser
2) flush the compressor of the old oil as R134 is not compatible with R12 mineral oil.
3) Add PAG oil.
4) Change the fittings which is simple as the new fittings will screw over the old ones, you just need to remove the valve from the old fittings and you need to replace the drier.
5) Pull a vacuum for a good hour
6) Charge the system.

The problem with R134 is that it runs at a much higher pressure then R12, because of this, it is recommended that you charge either by pressure or at 80% the original volume. The R134 molecules are smaller then R12 molecules and because of this, the system will develop leaks out of the hoses. R134 systems use barrier hoses which are lined to prevent this.

One alternative that is becoming more and more popular here in the US is using propane. Propane is very efficient at cooling, carries the R12 oil and because it's molecules are bigger then R12 molecules, it can fix small leaks.

The obvious risk to using propane is that it is flammable and I would certainly keep a fire extinguisher in the car if I use it.

If you can find R12, then stick with it, just make sure that your system is leak free as it's usually very expensive.

[OneCarefulOwner]

JPB: that's certainly one option… I'll keep it in mind!