``````Sloth wrote:

The trouble is with places charging a flat rate of say £50/fill regardless of car, is that most cars take 6-700g... then we rock up with a P38 needing 1200-1380g. Suddenly they're barely making any money taking cost of gas and their time into account. At the same time... that's not my problem.

The DIY refill things I'm not a massive fan of because in the UK, they can't legally contain actual refrigerant anymore. So long as the pressure on the low side doesn't end up massively high, it should be okay. But it can't beat weighing it in. Equally.. if the system is empty and has air in it, you're filling a system with an unknown 'refrigerant' as well as the air, which will have moisture in it and emulsify the oil... all ending in a mess. Pressures probably all over the place too. Then you have those with 'stop leak' additives in, which I've seen quite a lot of stories of TXVs being blocked up as a result, needing evaporators pulling out to replace etc.

I'm not sure on the R12 idea - I believe propane is mostly compatible in properties with R22, and R290 is basically just propane with a very low moisture content. Just has the slight downside of the old flammability issue... although the new R1234YF is too, so I guess car manufacturers aren't that bothered. I know a lot of us drive around with LPG plumbed up all over the place, but to me you're much more likely to end up with a big leak on a condenser when a nice pointy stone hits it or you have a collision with something in front....

I think the other potential concern is if you ended up with a leak where it leaked into the cabin area - possible given the evaporator is linked to that area by its job. Also I've seen the results of a compressor left open to the air (granted it was for an extended period due to a hole in the pipework) and can confirm it will knacker them completely. If the photos below work you will see what I mean.

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Where does the trade turn to when buying driers? I plan on getting the Elgrand back on the road soon then fixing it's AC system but the system has been open to atmosphere for a long time so I think it will be best to change the drier after pressure testing.

My pack of new o rings arrived today, I got the Toolzone kit in the end. It had all the right sizes where slightly cheaper ones didn't.

What's best to lubricate them when installing?

Ideally the same oil that goes in the ac system

Ah, I don't have any of that.

I'm guessing Vaseline would be bad then?

PAG oil is what should be used - a small bottle can be had on eBay and will last ages. Or some kind of mineral oil.

RutlandRover wrote:

Ah, I don't have any of that.

I'm guessing Vaseline would be bad then?

Probably yes, using the pag oil should be fine, as you know the seals are designed to withstand being exposed to it and it won't do any harm inside the ac system either. Couldn't remember what it was called else I'd have said above.

I'll grab a bottle of that today then. ECP have PAG46 on offer at the moment. £6.50 vs around £10 for PAG100.

Not sure if its the right grade of oil for the compressor but as all its doing its lubing the o rings it should be fine. It'll have the right oil pumped in when I get it regassed.

My bottle is PAG46 - so long ago when I bought it but its been fine :)

See if you can get some UV dye put in when you have it gassed if it doesn't have signs of having some already - will make finding leaks in the future easier.

Well that was a result. The website shows 250ml for £6.29.

Got there, gave then the part number and she went off to get it.

Came back with a 1l bottle, insisted it was the right one and only charged me £6!

Quite what you are going to do with the remaining 995ml is anyone's guess. I've found that there is usually enough dribbling out of the pipe when it's disconnected to use for the seals.

Keep it for the next 199 air con rebuilds!

Like my half kilo tub of red rubber grease... Something need grease? Got it covered ha.

I think we've all got a tub of antique red rubber grease somewhere. I've often wondered if you can still buy it, my tub must be at least 40 years old.

Well, that's all the o rings changed except the ones on the bulkhead. The sun had been shining on the engine bay all morning and everything made of metal was very, very hot.

The kit that Clive recommended was good for all of them except the smaller pipe in the compressor. It had one that was the correct ID but it was too fat. When I did the bolt up and the pipe pulled tight the o ring pushed out and got cut. Luckily I had one that worked in a small kit of spare o rings that came with my new condenser a few years ago.

I called LR to see if they had the right one in stock but that was a useless phone call. Their diagram is the same as the one in LRCAT, not surprising I suppose. It just has a list of o rings ranging from 7mm to 17mm I think. I measured the pipe where the o ring sits and it's 11.93mm. They told me I was wrong, there's no 12mm, only 11mm or 14mm. Then they said they don't keep them anyway and didn't want to talk anymore.

Surprised that LR didn't have one of those small O rings. Britcar list it in both Brit-Part and Land Rover versions. Looney tunes price, about £5 and £8, but I guess its not a common size. Which is odd as one would have expected it to be used on "lots" of air con compressors.

Forgot to mention that the Rovers North site page I linked to https://www.roversnorth.com/category/696_range_rover_p38a_99_02_heater_air_conditioning comes back with the correct part number if you click in the lists.

I remember stealing a list of sizes from somewhere at least partially annotated against part number but thats another thing lost in computer-space.
Had a re-organise & sort out a couple or three years back and lost some useful stuff.

Clive

RND587/STC3177 looks like the one then.

I did come up with that part number before but can't remember where I saw it. When I looked it up some parts places were listing it as GEMS only though.

The issue LR were having was that they could see all the possible o rings and their sizes but had no way of saying which one went where - so they didn't know which one I needed.

I've bought a 2 part front to rear aircon pipe and rear evaporator for my Elgrand but the dismantler purposefully let a lot of the pag oil drain from them.. Should I buy some pag oil and put it in when I've fitted the bits before I go for ac recharge (and if so how much)? What pag oil to buy and should I get some UV dye? Pipes and bits were drained by standing them upright. In fact would it be a good idea to flush the front to rear pipe with something before fitting?

The few times I've had it done, the PAG oil gets put in by the machine, the better places will put the dye in at the same time as its already mixed with the oil. You might want some though to help when your assembling the pipework (allows the o-rings to slide a bit easier)

I know the machines put some oil in but I think they only put as much back in as they take out? And what they take out usually won't be much?
But I'm changing a couple of components that would usually have oil in them, most of which wouldn't usually be recovered by the machine, and the components I'm refitting will have less or no oil in them... net result less total oil in the system. So do I have to put some in? Will only take a drop for O rings, sure I'll be able to scrape a drop from the system if I don't have to buy new oil.