I have one point of advice to give and one I would like to receive. When I bought my XJ40 it had numerous problems-it is a low mileage car and was very cheap. Somewhere along the line someone "recharged" the AC with a kit. The AC tech tells me that the system is shot because the kit injected butane or propane to raise the gas pressure only. This has corroded the AC system. If you are doing a home recharge my advice is to make sure the R134 can is really R134 and not a volatile gas. Propane retains moisture, I suspect this is where the corrosion came from. The compressor was completly corroded and shot. I have installed a new compressor. Sanden SD7H15 to replace the old SD5. This is the replacement spec'd for the XJ40 with R134a. I bought a new one from truckersac.com for around $240US. I'll replace the system o-rings and receiver/dryer. So at this point I have two questions, not one as promised.
1) anyone know of a good cleaner that can remove rust from the fittings in the AC?
2) the new SD7H15 has a different manifold layout. That's AC compressor manifold not engine manifolds. The old system had the Discharge side connected to the condensor, I think. So much for my notes. Should the Discharge port be attached to the condensor? Unfortunately the new manifold will not accept the reservoir, I think it is a second accumulator, without modification to the mounting. That leads to my confusion of what goes where since this reservoir is in line with the condensor and then attaches to the compressor. This is my first time with the inner workings of AC, I don't even know enough to be dangerous. The old compressor also had what appears to be a vent and a pressure switch on the discharge portion of the manifold. Anyone have experience in this area? Is it possible to leave the pressure vent off the system since there is no port to attach it to on the new compressor? The old manifold will not fit on the new compressor. So that is not a option. Any advice would be greatly appreciated.

 

While you're waiting for someone who knows what's what with cars other than late cars like mine (factory R134A), you might want to check out the XJS forum. IIRC, a few members over there have swapped compressors.

I'm surprised you're dealing with internal "rust" though - AFAIK the whole shebang (other than the compressor internals) is aluminum and copper? Corrosion is possible of course (my condenser was perforated from corrosion due to moisture/leak/inactivity) - but rust?

After you figure out how to reassemble the system any remaining moisture can be purged with a good long (24 hr?) vacuuming down, and no moisture = no further corrosion, right?

I would imagine that whatever corrosion has taken place on your rig would reveal itself with a leak? Of course unless we're talking gaping hole here, you'll have to re-assemble and re-charge or do a nitrogen test to identify the leak.

Unless you're a dab hand at aluminum welding, you'll have to replace the leaky component.

An alternative might be to try reinforcing the area (if the area of the leak is accessible) with the application of the A/C tech's friend, "LACO heat stik" a 60 second cure epoxy designed for temporary a/c repairs. After you plug the leak with LACO, a sleeve of JB weld over top of the area makes the "temp" repair semi-permanent (3 years and counting on my own LACO repair)

As far as the layout of the hoses goes, maybe the late factory R134A system diagram shows something? I appreciate things may be different with a converted R12 system but possibly working between to two drawings you can see what goes where??

R12 system:
http://www.jaguarclassicparts.com/uk...rigerant-hoses


R134A system:
Refrigerant Hoses-4.0 Litre - Parts For XJ6 & XJ12 from (V)667829 to (V)708757 - Canada/USA | Jaguar Classic Parts UK

Good luck eh

Larry

 

Lawrence, thanks for the input. The corrosion looks like rust on the ends of the fittings and all through the compressor vanes and valves. Sanden has pictures on their website in the SD7 service manual that look exactly like it the corrosion. The lines all appear to be solid. The fittings look like they are steel with an aluminum coating but I can't be sure without damaging them. There does not appear to be any corrosion through the fittings. The problems I have are mounting the pressure relief valve and switch on the manifold and aligning the compressor so I can attach the accumulator and evaporator line. I took the manifold off tonight and it definitely will not attach in any other direction so I am not able to adjust the suction and discharge line positions. I will try again tomorrow and see if I can get things attached. Ron.

 

Sorry I can't be of any help regarding the assembly - I don't know if any of my parts car bits would be of any help, but keep in mind I have a complete factory R134A system that was working when I removed it from the parts car about a month ago.

cheers

Larry

 

Hi Ron,

When I replaced the compressor, receiver-drier and expansion valve on our '93 due to compressor failure, I took the old components out, sealed the ends of the lines with plastic bags secured with rubber bands, and drove the car to the local A/C expert for a complete system flush. He has a machine that power flushes the system with some sort of solvent. I wonder if that might be sufficient to remove residual corrosion from your system?

After I installed the new Sanden compressor, R-D and EV, I took the car back to the expert for a good vacuum test. He pulled the system down to nearly a perfect vacuum and it held all day.

I hope you can get your lines to fit the new compressor without too much trouble. I don't recall having any trouble in that regard, but I was working on a late car similar to Larry's.

Cheers,

Don

 

Thanks for the inputs. The local AC tech I have talked to has been very helpful. I have blown out the lines. I found out the piece I thought was an accumulator is actually a muffler. I will be sending them the unit after I install the compressor. Then they will flush, vacuum test and recharge. Unfortunately I dropped the compressor when I was installing it-very annoying. I will have to replace the clutch bearing. The new compressor is difficult to install since the manifold is slightly rotated from the original. Once again this is the compressor Sanden tells me is the current replacement for the original. The tech did tell me that Sanden is top of the line for quality. What I saw when I took apart the original seemed high quality. There is one bracket I will have to make due to the slight mounting change, after the bearing replacement. Looking forward to having this fixed. Thanks again to all who helped, or wanted to help.

 

Hope things go well. Sounds like you possess good knowledge and skills and have the help of a good pro. Please keep us informed.

Cheers,

Don