I need to replace my a/c compressor and I need some advice. I will be replacing the expansion valve and drier alao. When looking for parts, many of the driers say direct replacement but they are the vertical type not the horizontal like I need. Kirby's book says that a gm a-6 compressor should work. I would like some advice from someone who has replaced these parts so I get the correct ones. I would like advice on flushing the system also. I have a vacuum pump, guages and 30lb bottle of r134. Any information will be greatly appreciated.

 

A Sanden compressor is a very good replacement for the old GM one, and it can be easily fitted with the modern clip-on type of fill fittings. It makes changing A1 and B1 plugs much easier as it has a significantly smaller diameter. The horizontal dryers are readily available from the normal sources and (over this side) on ebay. I scrapped that funny canister thing attached to the compressor which is meant to be a muffler of some sort, with no ill effects at all.

Replacing the flexible hoses is important with the R134 as earlier ones will allow the gas to permeate out through the actual tube material! Take advice from a proper a/c expert before doing the first fill, as getting all the air and water vapour out from the old system is a must before refilling.

Be very careful to support the other side of the fittings with a spanner before unscrewing the hoses and the expansion valve, as otherwise you will tear off the copper pipe of the fitting rather than unscrew the hose.

Greg

 

The car was built with the GM/Harrison A6 compressor. These work great...but are heavy and notoriously parasitic. As mentioned, a Sanden replacement is a popular, more modern option. Or, there's an outfit making an aluminum A6 replacement that is lighter than the original and hopefully less parasitic.

If you stick with an original A6 set-up and buy a replacement be aware that there are several minor variations in A6 compressors over the years. Many will tell you "they are all the same" but they're not. The difference most likely to crop up is
'superheat switch type' versus 'HSLP type'. Unless previously changed/modified, your '86 will be a superheat switch type. This system is easily recognizable by having the small 3-terminal thermal fuse near the compressor

The HSLP type is generally preferred, however, as it eliminates the one-use-only thermal fuse from the ciruit. If you have the superheat switch type you can convert to the HSLP type with a minor wiring change. Make sure to get the HSLP (high side, low pressure) switch itself when you buy the compressor.

Cheers
DD