a/c help

beany · 12-12-2009, 01:47 PM

I have been trying to finish up my rebuild on my 80 sc ac. My question is that do I need an o ring on all the hose to condensor , dryer, evaporator fittings? I have been trying to pull a vacumn (which it does) and hold it before filling. I suck down for three hours and then recheck later and the vac is gone. Any help would be appreciated.

Mitch Leland · Mitch Leland's Garage

Quote:

Originally Posted by beany

I have been trying to finish up my rebuild on my 80 sc ac. My question is that do I need an o ring on all the hose to condensor , dryer, evaporator fittings? I have been trying to pull a vacumn (which it does) and hold it before filling. I suck down for three hours and then recheck later and the vac is gone. Any help would be appreciated.

Here ya go... See item 19, also remember to use "ester oil" on the "O" rings.

beany · 12-13-2009, 07:42 AM

Thanks for the help, you answered my question.

Mitch Leland · Mitch Leland's Garage

Beany Man,

Also you don't need a heavy hand when you tighten the nuts on the A/C fittings with the "O" rings. Just a good snug tightening will do the trick. There's a lot of information here if you'll do a search on everything, "A/C"...

beany · 12-13-2009, 01:16 PM

I made a trip to the local auto store and purchased a couple boxes of assorted size nitrile o rings. I hope I have been installing them correctly. The fittings seem to be the flare type and I have fitted a small size o ring so that when the fittings are tightened up the o ring is squeezed between the two fittings. Most of the sizes seem to be # 8 size orings. If this sounds like I have been doing it correctly I will start on the harder to reach areas, the evaporator and front condensor. Thanks.

Jim Sims · 12-13-2009, 04:20 PM

Flare type A/C fittings do not use o-rings; flare fittings use metal to metal sealing. Using "Nylog" sealing compound on the flare fittings sometimes assists in achieving a good seal.

Jim Sims · 12-13-2009, 04:34 PM

If the fittings on the ends of the hoses look like this you have flare fittings:

Jim Sims · 12-13-2009, 04:44 PM

If the fittings on the end of the hoses look like this you have o-ring fittings:

Typically on o-ring equipped 911 A/C systems there are # 8 o-rings on the fittings between the compressor and the deck lid condenser and either #8 and/or #6 o-rings between the deck lid condenser and the front valence condenser. Then there are #6 o-rings between the front valence condenser and the receiver/drier and the evaporator. Finally #10 o-rings are used between the evaporator and the compressor. There may be variations in the o-rings used depending on the compressor and condensers installed.