Most GM A6 compressors fitted to WBs have metric mounting bolts. Only the early ones have SAE bolts. If the original sticker is still in place the metric ones are a identified by a blue section indicating that it has metric bolts.

It's the threads in the rear of the case which matter most. You simply can't use 10mm bolts into a 3/8 threaded hole or vice versa.

A 'reco' one will be fine, depending of course on who 'reconditioned' it.

GM haven't made any of these for donkey's years, so any 'new' ones will be NOS or cheap clones made in either Mexico or China.

Dr Terry

Edited by user Thursday, 3 March 2016 7:06:38 AM(UTC)  | Reason: Spelling

I'm going with a reco unit. I rang the bloke who sells them in Melbourne and he claims that AC Delco remanufactures them in the US using cores sent from Oz. Hmm, dunno about that..

Anyway, my plan is to get the reco unit and fit it myself, the get a mobile a/c bloke to charge it up and see how it goes.

I know that the system has not worked for more than 3 years (the belt is off and so is the front of the compressor -- the clutch?) so are there any other parts that def will need replacement? Rec/drier, expansion valve? Dumb question, but what's that large aluminium canister in the WB a/c system, near the a/c fan and box?

Any parts that are going to be hard to get that I should order before I get the a/c bloke to come over?

In reality, it's a small amount of gas in the system, and the need to get a stoich ratio at the same time as a spark, the chances of kaboom are low.
Most leaks are at joins, or from impact damage to the condensor or pipes. However, if a particular model of car is renowned for evaporator core leaks (and some of them do corrode through and leak inside the cabin - like a workmate's mazda 6 that near suffocated him), then I would run away from a flammable hydrocarbon as fast as I can.

Hychill has it's place for a budget "get it going" retrofit on an old & tired R12 system that someone wants to get a few more years from.
If I was putting a new system together from scratch - especially with the cost of a compressor & other major parts, I'd be going the tried & proven R134a route (and have done so).

I had a VC SLE converted to R134a (it ran the A6 compressor) and the performance was excellent - but other work was required.
When I did my VL Brock, it was no question to go 100% with R134a.

The existing hoses & clamps will handle R134a fine, just add to or modify the existing condenser fan arrangement to alleviate any problems of the high side pressure going ballistic.This is a common mod, retrofitting R134a into older cars.

R134a works well in the WB/VB/VC style Harrison systems, much better actually than the HQ-HZ type.

Dr Terry