Working on my 92 again, I am tentatively beginning to plan to think about considering the possibility of attempting to figure out how to repair the A/C system. It worked when I got the car (13 years and almost 35000 miles ago). Then, some time back with no provocation whatever, the compressor self destructed. I got a second compressor, installed it and had the system vacuumed, recharged and then working for about 2 weeks, until it simply stopped. My guy told me there was an obstruction probably at the H valve. At that point I elected to leave it go and took the belt off so the replacement compressor would not get ruined.
It has been a few years since then and on initial checks I now find that this second compressor seems to be frozen after having been idle for so long. I have researched buying yet another unit and find it to be cost prohibitive for such folly. However I have a similar Sanden compressor which I took off of my truck and one from the xj12 from earlier this year. The one from my truck only needed a clutch magnet but since that system was already discharged at the time, and I had to remove it either way I just changed the whole thing. The 2 spares seem to be nearly interchangeable with each other but the difference from them to the one for the 92 is that the mount bolt holes are perpendicular to each other between the 2 kinds of compressors. That is, on the wrong ones, the bolts would go across the body of the compressor, whereas on the correct one they go fore to aft length wise on the body.
Here is my idea---> Swap the guts of one of the spares into my correctly cast housing. I honestly think this is a deceptively simple SOUNDING idea, and that it may be simpler to build some kind of adapter plate to mount an unmolested unit on the car.
Has anyone tried either of these? Is it even possible to remove whatever is inside without damaging the parts, never mind putting them all back together correctly into another case? Thanks guys!

 

Having disassembled one of these Sandens (unnecessarily) and the changed the clutch and bearings (the harmonic balancer was the issue ) I would suggest the best thing to do first would be to pull the apparently frozen replacement compressor off.

Most likely the clutch is very stiff and possibly stuck and/or bearing seized. Unlikely the compressor pistons are seized unless you ran it without oil.

There is a few good tutorials on servicing a Sanden model very similar to ours on youtube, one in particular, I'll see if I can find it again. Very helpful.

I found I needed a puller to remove the clutch and you will need an inner and outer cir-clip pliers to get the bearing out too. I bought a kit to pull the clutch on eBay but it was only partly satisfactory, more for a Harrison IMHO however I McGyvered it to do the job. Be careful of the shim on the shaft when you disassemble/reassemble as it is specific to YOUR compressor.

This was the video I took my cues from


Good luck Jerry

Larry

 

Thanks Larry. I did try spinning the unit using a small pry bar nestled among the rings on the front plate. But I certainly should look deeper at it first since I didn't test the drive belt section separately..... as always, more later.

 

Jerry I forgot I posted a few pics of the compressor teardown in this thread too, have a peek

https://www.jaguarforums.com/forum/x...-issue-220992/

Also, before digging in, you might want to think about this ...If the system quit because of low gas (leak) or faulty switch etc you can do momentary compressor test by shorting the A/C relay socket on the RH firewall with a jumper. If the clutch spins up, the compressor is quite likely fine. Of course the car has to be running as well!

I learned this trick back in 2012 from Nick when my car had no blowers, heat or A/C ...

here's Nick's actual advice:
Larry

 

This thread turns my stomach a bit. I’ve had lots of experience dealing with various failures of the AC compressor(s) in my ‘92 as well...

One original, one “rebuilt.”

The rebuilt compressor had issues with stripped threads on the rear housing for the low-pressure cutoff switch, and the high-pressure relief valve. It also had a mounting ear with an out of round hole for the mounting bolts, which I had to correct.

It started when the OE pressure switch started leaking on my original compressor. I replaced the switch with the original part ($75+ IIRC) and within months, that one failed too, the plastic portion blew right off and spewed Ester oil (car was converted to R134a) all under the hood on the highway. The AC was mediocre at that point even after replacing the condenser, receiver dryer and expansion valve, along with evac and recharge. The original compressor was already getting noisy before this point so I decided to replace with rebuilt after the catastrophic failure.

I eventually decided on converting the car BACK to R12, so I took the EPA test, got my certification card, purchased the NOS R12 cans on eBay, a used Robinair R12 manifold gauge set, both new high and low side hoses with R12 fittings, a shop air flushing kit with solvent, found the correct spec Mineral oil (could only find it in a gallon), and went to town with the rebuilt compressor, draining the prefilled Ester oil (compatible with R134 and R12, but not as good a lubricant as mineral if you’re just using R12) and replaced with mineral.

I found the threads stripped so I swapped the rear housing half of the compressor over to the rebuilt one, I have had zero issues with leaks at the compressor or anywhere else in the system. Charged with R12, the system freezes me out like it never had with R134a. The evaporators on 92 and older cars are just too small to work efficiently with R134a. Head pressures are less, and the sight glass on the receiver dryer works. No bubbles, no leak. Simple as that. I am so happy I converted back. With new barrier hoses and modern o-rings and seals, you should not get any leaks. The R12 molecule is much bigger too, so less leaks in general.

My advice is this... Whatever you decide to do, do it right the first time. Mounting these compressors is such a PITA. I wouldn’t want to have to do it again, even if that meant buying new vs rebuilt.

Compressor failure makes such a mess out of the whole system. I would definitely recommend flushing every hose and component you can with correct solvent. Old oil, metal shavings, bits of desiccant material, gasket material, etc. If you have the system open, definitely, definitely do a proper flush, and make sure you replace the maintenance parts like receiver/dryer, expansion valve.

Nick

 

Thanks Nick,
I would like to flush the evaporator and the condenser. Ultimately I plan to replace the hoses and the dryer with new. Any thoughts on home flushing of the cores? Kind of flush fluid? quantity?
As far as swapping housing parts- which is my intent if feasible- any special tools needed or springs waiting to launch themselves? Better yet, did you take any pics of the process?
I feel like im asking too many questions and just need to gather my hammer and chisel and go after it.

 

As far as flush goes, I have used both the canned solutions with the built-in hose as well as the shop-air style which has a refillable canister you attach to an air compressor. If you use your own solvent you want to make sure it's compatible with A/C systems and most of all, that it evaporates completely, with no residue left behind.

I was lucky that I didn't have to deal with the front-end of the compressor, only the back half, which unbolted easily, and after removing the through bolts, the half just pulled up and off, exposing the valve plate and gasket. The original plate was covered in oil, green leak detector dye, and a little bit of sludgy material. I used the gasket and valve plate from the rebuilt unit, which was of course new and shiny.

I believe front end disassembly would be more involved, but I can't say for sure.

The compressor is the Sanden SD7 series, you may be able to find a rebuild guide somewhere on the internet.

Good luck,
Nick