What are the fittings called?

[Mobius]

I have a 79 GMC C10 with factory air. I’m installing a March serpentine conversion soon that gets rid of the huge factory compressor and uses a passenger side low mounted Sanden 7176 unit. When I go to order/purchase custom A/C lines, what size/type are the fittings that run to the accumulator and the condenser from the compressor? I’m going to buy an adapter for the Sanden compressor that says it has #8 and #10 (iirc) fittings. Are these what is referred to as O-ring fittings?

 

[dvdswan]

Those would be AN fittings. IIRC #8 is 1/2" and #10 is 5/8.

 

[Mobius]

Thanks. What about the fittings at the other end of the hoses? I’ll need to know what the fittings are at the accumulator and condenser, too. Or are they all AN?

 

[75gmck25]

I went through this process several years ago, but I don't think I have any detailed notes.

I think these are the specs they used when they made my hoses.
- Compressor has #8 (1/2") #10 (5/8") O-ring fittings
- New parallel flow condenser has #6 (3/8") and #8 (1/2") O-ring fittings
- Accumulator is #12 (3/4") O-ring - 1/2" hose runs over to #10 fitting on the compressor

The picture in this article is the general design of my '75 system.
https://www.buyautoparts.com/howto/AC-Accumulator-Orifice-Tube-System-Layout.htm

Compressor to condenser top- #8 to #8 O-ring
Compressor to accumulator #10 to #12 (3/4") o-ring
Accumulator is mounted on the upper 3/4" fitting on the evaporator - no hose
Evaporator to condenser #12 O-ring to #6 O-ring

My '75 evaporator has the orifice tube in the fitting on the evaporator so the fitting is large (3/4"). If you use a larger diameter hose for this fitting, you can't crimp on a #6 fitting for the other end. They had to custom braze two fittings together to adapt a smaller diameter hose to the large fitting on the evaporator/orifice tube. I think they changed this design on later year vehicles, so you might have more standard size fittings on your evaporator.

Bruce

 

[Mobius]

Is the fitting on the factory condenser (from the compressor) also a #8? If it is, it sounds like all I’ll need is a hose with #8s at each end to run from the compressor to the condenser, and one with a #10 and a #12 to run from the compressor to the accumulator.

 

[yevgenievich]

First page of coldhose.com has the dimension tables so you could verify the fitting sizes. But generally as was posted above should be correct.

 

[75gmck25]

Also take a look on Rockauto for your condenser and evaporator. They usually provide a parts number and fitting size for all the major A/C parts.

When they replaced my accumulator, the original had one fitting on the bottom of the accumulator, and there was a separate J-tube like this one, which looped back up to connect it to the line to the compressor https://www.rockauto.com/en/moreinfo.php?pk=814892&cc=1159073&jsn=462.
The A/C tech swapped in a newer accumulator like this one https://www.rockauto.com/en/moreinfo.php?pk=815084&cc=1157408&jsn=664&jsn=664 (from about an '84 GM truck), which had both fittings on top. As long as the clocking of the fittings is right so that the hose to the compressor points in the right direction, it makes for a simpler assembly and easier hose routing. It also moves the hose connection upward, which makes it easier to route it over the top of the engine to a compressor on the driver's side.

Bruce