OK, I read through the entire thread.
vstech and leathermang - I'll make you guys a deal - if you help me through my A/C 'rebuild' I'll document it all and write it up so it summarizes this thread into an article and DIY with FAQ's. You guys are warriors answering the same q's every year, so I want to make it easier for everyone in the future.
Normally, being in Boston, AC is not high on my list, but I have gotten so frustrated with no shops around here knowing what do on any A/C system, Id rather just buy the gear and do it myself.
I am rebuilding the 82 300D's AC. It is my fiances car and I want to hear complaints on how cold it is
- It had been converted to 134, but I would like to deconvert it to R12
- new evaporator already installed
- new condenser to be installed
- new compressor and o-ring kit from Carlisle in SA, TX is sitting at my feet
- new R/D purchased
- new expansion valve installed
- new upper manifold A/C hose. I'd like to re-use the lower manifold if possible.
tools i have acquired:
- robinair 2 stage 1.5 CFM vacuum pump
- R12 and R134a gauges
- A/C leak detector
I plan to in this order:
this fall:
- flush entire system and blow clean with dry shop air
- replace all o-rings using nylog sealant
- add 4 oz of mineral oil to compressor, 2 oz to evaporator, 2 oz to R/D
- pull vacuum for hours
- charge with 4 oz of R22 and inert gas (*) to check for leaks
next spring (car sleeps while salt is on road):
- re-evacuate, replace R/D, hold for an hour, then charge system with propane (j/k...seeing if you guys read this far) R12.
Questions for the experts -
(*) 1.) Can I use MIG welding gas (75% argon, 25% CO2) as my inert gas for the pressure test? I ask because I already have plenty of it.
2.) For the deconversion, I need to go back to R-12 fittings. How can I tell if I have damaged anything by taking the 134a fittings off? That isn't entirely clear.
3.) For the blowing out of the lines with air after the flush. If I use my air compressor with an inline desiccant and oil/water separator - is that OK? Even if there is a tiny amount of moisture that gets through, won't that boiled out during the vacuum step? (I could use welding gas here, but I don't want to waste it)
thanks, looking forward to learning to do this the right way...
dd