Late Model A/C Replacement

[jtehfreaks]

For the past 10+ years, the A/C on my car hasn't worked; I've finally gotten tired of driving around in the heat and humidity and ordered a bunch of replacement parts from Griffiths, to include some hoses, condenser, compressor, dryer and expansion valve. Is there anything I need to do before I start removing parts? Should I potentially get the system flushed since it's been sitting for at least 10 years without use?

After I get everything installed, how do I add oil to the system? Should I just install everything and take it to a shop to get it oiled and charged? I'm running into what feels like a decent bit of new territory, so the more info, the better!

[mytrplseven]

At this point I'd recommend letting a local shop do it so they can evacuate the remaining gasses, replenish the oil and new Freon and change it over to R-134 (if you're still running R-12). Make sure they add a dye when they replenish the gas so if there's a remaining leak, they can locate it.

[jtehfreaks]

I'm definitely moving over to R-134a, I ordered the conversion kit from Griffiths when I ordered everything else from them. Good catch on the dye, I'll have to remember that when I get everything installed.

[944 S2]

FYI the oil is filled before you put everything together not afterwards.

[thomasryan]

AC guys with reclaiming machines kinda frown on getting dye into their tools of their trade.

It is best to drain the shipping oil in the new compressor to get an accurate fill.

Lube all o-rings with whichever PAG or ester you will be using in the system.

Most cores are stored and shipped under vacuum. Listen when you remove the shipping plugs.

If possible, insulate the expansion valve. They work better and make less noise that way.

Be sure your fan relay triggers with the high pressure switch before operating the unit. It won't hurt to clean the dead bugs out of the radiator while the condensing coil is out of the way.

Vibration shortens the life of the cores so replace the padding and mounts if they are aged.

[jtehfreaks]

Thanks for the information!

So I just pour the ester oil into the compressor, give the pulley a few spins by hand to lubricate everything, and then mount it to the engine? I've read that you're supposed to add some oil to the dryer too. Would anyone happen to know the amount of oil I should add to each component?

The expansion valve is coming with some kind of weird looking black tape, I assume that this is meant to insulate it, right? What's a good way to check that the relay is triggering the switch, I figure I can at least do that now while I wait on everything.

[mattdavis11]

If you are going to be using R134a, then use pag 46. The system should need 6.5 ounces of oil. Flush the evaporator coil, and ALL of the lines. Add oil in various locations, 1 in the drier, 2 in the condenser, 1.5 in the evaporator, and 2 in the compressor. Rotate the compressor clutch after installing and before adding refrigerant. Do not add refrigerant as a liquid all at once, you can damage the valve plates. Compressors do not like to compress liquids, they compress low pressure gas. Go slow.

Good luck!

[thomasryan]

the black tape is to insulate the valve.

I've earned a few paperclip tattoos from making test jumpers. if you have two pressure switches, look at the numbers stamped into the brass. the higher number should be the high pressure switch.