My well planned weekend did not go so well. Once again screwed by crapy American made garbage. No surprise there. Fitted a new A/C condenser and of course I want new o-rings. The kit from Santech out of Texas had nothing even close to fitting properly. This also means that I was not going to wast my time installing a new expansion valve or open up all the fitting to the rear AC..... I doubt if any o-rings from the kit would have fit well. And dont get me started on the valve stems... those did not fit either....

Suggestions from people with no first hand experience with working on the system.... does anyone know of a o-ring kit that is a proper fit? I do have a generic metric kit, but even those were not a good fit. None were thick enough. Plus I am not trusting of the quality of those black nitrile rings in a system like the AC.

For reference the kit was P/N: MT2622 - a bag of numerous purple o-rings.

 

The GPD o-ring packs are no better. I share your frustration. I have a bunch of o-rings in my arsenal, at work and home. The only thing for certain is that no matter how many you have, you won’t have the right ones. I re-used ones that were good and used the next closest I could find after laying them all out and eliminating one-by-one. I wish I could give you better info, but I just can’t.

When I replaced a ford system, I bought OEM seals. Those were a confident fit. I’ve done both my LR3 systems with aftermarket. They are sealed, but the aftermarket o-rings leave low confidence.

 

Yeah, it is a cluster..... I have spend hours searching for info and I have made a lot of progress.

So far the front and rear lines use these o-rings. I have not dug into the dash area (besides expansion valve) or rear AC evap area.

JUU500010 (used at condenser and solid line junctions)
JUU500020 (used at condenser and compressor, basically each end of the short single flexible hose) // LR031797
JUU500030 (used at sold line junctions)
JUU500040 (only used at compressor) // LR031798

This person bought a couple and measured and concluded some dimensions, but they were off it seems:
https://www.disco3.co.uk/forum/air-c...gs-190494.html

So after some digging I was able to confirm these:
JUU500020 = 10.6 ID x 2.4 CS
JUU500030 = 13.6 ID x 2.4 CS
So for the two above, I am very certain that is the size needed.

For JUU500010 I have not had a ton of luck until maybe tonight. On yet another parts list site while searching this very part number I came up with a Disco 4 3.0 V6 Diesel in the results to a list. On that list catalog number 19E889B came up with 6.75x1.78. Which seems about right using my calipers, better than the 6.5 that Disco3UK person estimated. The issue is that the same oring location for a LR3 shows as 19E889C, not B. Which usually implies a different part. FYI, these catalog numbers are used by many and are the same. But the location, physically, is the same. So I backed out and drilled down to the condenser itself for each Rover. Again comparing the 4.4 V8 that I have against an LR4 V6 3.0 Diesel. Both catalog numbers for the condenser are the same, 19712. So the oring needed should be the same. And sorry for the novel, but I wanted to explain how I got to it incase someone sees a flaw in my thinking here.

So then JUU500010 should be 6.75x1.78 and interestingly even the online shops confirm this one. And going back into catalogs I also found this, but not sure why the "catalog" part numbers are different for the same Rover part number.



So that leaves JUU500040 which is at compressor. I found references only for 23.8 but no cross section, so hard to say for sure. Tonight I did find that this part references an LR part number of LR031798, which so far has been of not help. But having two part numbers does expand search results. I suppose if I really wanted it, I could spend the $10 for one or-ing. But at this time I do not plan to do the o-rings at the compressor. Also it may be Ford part 1W1Z19E889DA......





As for expansion valve, I believe there are four o-rings and not all the same. I have not dug into those because most expansion blocks come with new ones like mine did. The LR part number for the o-rings is JEP500010.

 

Hats off to you for doing the deep dive work! Documenting this here is a HUGE help to anyone doing LR3 a/c work.

 

Small update on my end... After all that work I was not ambitious enough to replace every o-ring in the system. Only at the condenser and expansion valve is were new ones went. And the sizes above worked perfect at condenser. For JUU500020 I ended up going with 10.6x2.4 instead of 10.8x2.4 since that was the closest I had in the kit. Same for JUU500030, went with 13.8x2.4 instead of 13.6x2.4. So a slightly larger ID on both but it was not an issue. For JUU500010, the smallest of the rings, I went with 6.8x1.9 instead of 6.75x1.78 - in this case the ID is super close but the replacement is thicker. Was not an issue at all.

While I bought two kits, I only used o-rings from one:





If I end up having to take more of the system apart, I will update. I am temped at some point to pull the AC compressor and replace the oil inside. What came out of the condenser was dark. But at 225k miles, I am probably better off replacing it anyway before it detonates and sends metal through the system. Just remember, compressors come with all the oil needed for the system it is being installed into. But the LR3 has two capacities for oil/refrigerant based on having rear HVAC or not. So best to dump and remeasure. You also need to subtract for oil that is remaining in the system unless you flush it before you swap. The shop manual outlines the quantities that should be remaining in various areas.

 

That looks like a good kit with new seals for charging hoses as well. I’ve struggled chasing those down too. I just ordered one! Thanks for sharing your work and experience here!

 

replying to kick this back up to the present day, as I will be soon digging in and replacing the seals. A check with the UV flashlight looks like a 1970's black light poster. The AC worked last summer after I evacuated and recharged it but it did not survive the winter.

 

Ah... bummer.... and I hate to say it, but I am in your club. The very first time I fired up the engine to cycle the compressor, after doing literally everything by the book, I noticed it was pretty loud compared to OEM. A good search said that Nissen compressors can be louder so I shrugged it off. Then very late fall my engine sounded "off". Something was not right for a couple days when I started it. Then I looked under neath and saw oil on my guard and small pieces of grey metal. My compressor blew a MASSIVE hole out its side. While I could have done something wrong I tend to doubt it. Everything was flushed, replaced and vacuumed in excess. I used proper flush agent, nitrogen to blow things out, pro-grade initial vacuum AND then several hours of vacuum at home with a smaller unit. And it did work great up until late fall. So now I get to do this all over again because this summer is expected to be HOT. I will attempt a warranty with the compressor but I really think this next round will be a super cheap condenser and compressor. I don't want to blow hundreds again yet my original hope was that by doing such a specific by the book job it would have lasted 20 years again.... I am sad.