My 1977 20R celica A/C system has been running low on R12 freon for several years. Maybe it's time for a conversion to R134?<br><br>Any advice about what to do here? Do I trust the local shops to do the work (and charge huge $$$), or can I vent the system and install R134 myself?<br><br>thanks,<br>- Mark -

I would think that a person ought to be able to do that themselves. I urge though that you suck/collect the freon out/off the unit instead of just venting it. It's an environmental issue and a cost issue -- you can re-use freon and as I recall the stuff ain't cheap. Good luck.