How do I recharge my A/C?
 

I have a 1980 911SC and I have a place in town where I can buy some R12. I know it has to be connected to the low pressure side with the motor running but how do I know which is the low pressure side?

Also, how will I know when it is full?

You should change over to the more enviro-friendly 134A refrigerant. You can buy a kit to do this at your local auto parts store for around $50. It wil have everything you need to make the swap. The instructions show you exactly which port is which.

But I heard if you keep the old R12 system it will blow much cooler.

You shouldn't be doing it yourself if your asking these questions. Low side is from the smugglers box evaporator. You only put refrigerant in as a gas, cylinder up, not inverted. A liquid slug can break your compressor. You should wear a face shield. Actually, you should get someone who knows what their doing to help you. You need A/C gauges. Is your system still under pressure or is it totally dead. If dead, you need a vacuum pump. YOU SHOULD GET SOMEONE TO HELP YOU!!

Yeah I think I might, now that you just threw all that mumbo jumbo at me.

Good advice from the others. The low pressure side is the one with the larger diameter hose ( suction side ) vs. smaller diameter ( pressure side ). You DON'T want to mix that up or you could lose your fingers/hand etc. ( BOOM ).

Slantnose, I charged mine with 134 after finding leaks and doing alot of research into the matter, but I did have a vacuum pump and gages given to me. Theoretically it is possible to recharge using just a kit from Autozone, but there are alot of things that can go wrong and with 911 with a York compressor (with service valves and ports in tight spot), you would be wise to do some searching in this forum to study up on all that is involved. Here is a link detailing my DIY AC repair. Thus far it is still working great (good thing as it is near 90 today!)http://forums.pelicanparts.com/showthread.php?s=&threadid=226027&highlight=diy+yo rk+134

I attempted the easy and quick way of retrofitting my a/c the way you did Tim. However, I found that the fittings on the kit at the local auto store did not fit my '84. Do you recall where you got yours?

Jeff

Jeff, the old set of gages given to me have the R12 45 deg flare fittings. I simply took one of the connectors in the retro kit and temporarily installed it on the center port of the gages, then attached the kit supplied 134 can/tap hose to it. I did install a conversion sticker, but I left my old York service fittings intact. Once again, my system is working great (for a York), but I can't gaurantee everyone else the same results. The AC pros on this board know their stuff and in theory, I agree with most of their sound advise, however, my 1 yr+ budget conversion is still blowing cold. If/when my old York gives up the ghost, I will likely replace with a modern compressor. FWIW, I am kind of on the extreme end of the DIY'er scale.:)

Sorry about that. I didn't mean to mislead you. You should probably consider taking your car in for this procedure.

<i>I know it has to be connected to the low pressure side with the motor running but how do I know which is the low pressure side? </i>

SlantnoseSD, you "could" charge the system yourself, if you read enough posts in here, read a few brief "how to's" from the little booklet supplied from the refrigerant distributor at autoparts store and you had all the right tools.

I'm not suggesting it is not a DIY job, but I am suggesting you figure out how many hours you have in the day, how many bucks you have in your wallet and how you want to invest the two.

If you have the time then go for it. But if you don't feel comfortable then just have your favorite shop handle the procedure.

I've been thru most of the A/C threads on the board. Before I invest alot of $$ on new bits, I'm still hoping to do it the way you did. However, the kits at a couple of the parts stores around here did not fit.

jeff