Did a write up on it on LPGforum here's the link

Been wondering if the push in pipes at the evap end are some standard size and if I could get some from a scrap car to connect to hydraulic lines somehow. The bits of pipe left on my evap end fitting are probably too short and curved to connect anything to.

Should really upload some pics and link to them here, I've already uploaded pics directly to an Elgrand forum but internet here is acting up today and I'm short on time. https://forum.elgrandoc.uk/threads/e51-rear-aircon-leak.3203/

Morat wrote:

started leaking from the reservoir after a week.

Look on the bright side Miles, still better than if the noise was coming from the engine's bottom end lol!
Tried these http://acdoflancashire.co.uk/ ?
Maybe the Chinese merged the Yank PAS pump design with a Merc PAS pump design.. leaking reservoirs is a common Merc problem. Dunno why firms like Merc design their own bits such as PAS pumps only to make a less reliable part than well proven generic stuff that would've probably cost them less than their own design.

The aircon connectors arrived so without checking I think they only came from Manchester and cost £7, seem to remember seeing them on EBay from Singapore for less than £3. I bought the brazing rods from Machine Mart Doncaster for about £35 or £40 (so very similar price to that you paid Bri).

When I get time I'll try my option 3 (in my last post) and if that doesn't work (I think unlikely it will) I've thought of an option 4... Measure it all up and see if I can get a hydraulics firm to make full length rubber/flexible separate lines for LP and HP. But could a hydraulics firm get the fitting that goes into the rear evaporator right? They're not screw on hydraulic fittings, just smooth pipes with O rings, just push in and are clamped from behind by a plate that is secured by a bolt between the pipe holes.

BrianH wrote:

Couple of quid is a vast improvement over the £40 odd they had shot upto. I think the ones i brought were around £20 at the time, but they appear to have become much more scarce to find now.
https://www.ebay.co.uk/itm/R134a-Auto-Quick-Coupler-Bass-Adapters-Low-High-Side-AC-Manifold-New-SU/183151899017?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649

That's what I bought. Dunno where I got Singapore from lol, must have seen Singapore on another listing. Would have just bought another charge kit from Halfords rather than pay £40 for the bare port connectors, won't need the HP connector without a proper AC machine anyway.

I wonder if an LPG thermistor would be any good? They usually have the negative temp coefficient and are made in many various specs, 4.7K is very common, usually very cheap.

Took me a while to find the leak, it's not on the thick single pipe (with inner pipe) section, it's in an area where the single pipe has split into two pipes just a few inches before it enters the rear evaporator, the leak is on a short tightly curved section of the smaller diameter higher pressure pipe. I did order a couple of AC connectors as Bri suggested but they'll be ages before they arrive (from Singapore, just a couple of quid including shipping) so I cut my Halfords recharge kit pipe in half and attached the bit with the AC low pressure connector to a tyre valve, used compressed air to pressurise the system as Gllbert suggested. At 160 psi there was only a very slight weep of green fluorescent stuff from the narrow pipe but when I ran the AC compressor the weep turned into quite a spray. Seems the pipe has corroded / been damaged by eletrolysis from touching a metal panel while damp. On the vast majority of this model vehicle the front to rear AC pipe is one long section, on mine it comprises 3 sections. The 3 section is apparently only ever an aftermarket replacement part, to replace the original single pipe like for like the rear subframe has to be lowered but that isn't necessary with the 3 section aftermarket replacement. Disconnecting the rearmost section (with the leak) from the evaporator was a pain, the single M6 bolt that secures both HP and LP pipes had also suffered corrosion and snapped in half. Still, I managed to disconnect the pipes, then tried putting a couple of nuts on the broken bolt to torque up against each other to try to unscrew the bolt again... snapped again. I managed to drill the bolt out and re-tap the threads, so now I'm hoping I haven't damaged the evaporator by drilling.

With the rear section off I was able to better clean it up, which is when I found just how corroded it was. Still there were only a couple of little pin-prick holes so I set about trying to braze it over and thicken it up. At first the results looked really promising.. and I should probably have left it at that but I didn't! I realised that although it looked repaired I hadn't 'scratched it in' so had a go at reheating and scratching in... which is when the massive holes appeared lol! Then I tried cutting the corroded section out and brazing a bit of tightly bent 8mm copper pipe in it's place using 8mm internal diameter pipe nuts at each end rather than trying to braze copper to aluminium end on. No luck with that either and at this point it was 10pm and time I packed in.

I now have a few options - 1 drop the rear suspension and fit a full length pipe from a scappers, 2. try to source a second hand or new rear section for my 3 section setup, 3. try again to repair this pipe... Might as well try 3 first, won't hurt to try. But I'll try another tack using aluminium aircon pipe cut from a car that I'm going to scrap. One of the problems with 3 is the shape and length of the pipe, I'll have to really tightly bend the scrap AC pipe and don't know whether to still go with the pipe nut type idea or just try to butt braze the pipes together. I imagine butt brazing is extremely difficult!

I do wonder if brazing was a bad idea... If I could have used something like that two-part metal repair stuff instead, perhaps coated with a layer of TigerSeal and Jclips over the TigerSeal after it had set.

I'll add some pics when I get time.

Are the limited editions worth a lot of money?

The splice could work, not seen those before. I'll have to see where the leak is first and check diameter, not measured it but seems wider than 3/4"

I think Hugh mentioned incorrect idle speed when he brought it in for conversion?

I slackened the cruise cable which was tight. Even so, not sure if the throttle body spring is closing the throttle fully.

I'm on a few forums and only one of them allows uploading pics directly.

Clicked on this thread curious about what H&H is, thought it might be about old stage amplifiers... I'm not the most clued up person on Rangerover specs here lol.

Thanks Clive and Bri.

In the vids they just keep testing to see if the rods will melt when they touch the aluminium, though I take your point about a thin pipe could be cool at the edges but quickly get too hot and melt where heated. I picture going up and down quite a length of the pipe heating quite an area around the leak while testing with rods to prevent overheating a small area. Yet to see if it'll work lol!

Couldn't slide anything like a pipe over the outer AC pipe because it's in sections with wide fittings at each end, couldn't cut it to slide anything from the cut side because it has the inner pipe. .

Usually less pressure on the low side of an AC pump when running than there is with AC system turned off?

Seems plenty firms will recharge AC but very few will get involved in fixing it. Years ago I had a problem with AC on a Grand Voyager, it failed the vac hold test at Charlie Browns. Staff there pointed me to a guy next door who they said could repair AC systems so I left it with him for the day expecting him to stick fluorescent dye in it and tell me exactly where the leak was. When I returned he hadn't found the leak or put any dye in it, he simply told me there was a leak somewhere on it. Heated argument and I wouldn't pay him... WTF did he think I'd gone to him for when Charlie Browns told me the same very basic info for free. Think he just thought he'd chance having my trousers down, no chance lol. I really have a problem with people who do that sort of thing, there are plenty like it in the field of LPG too.

BrianH wrote:

You definitely don't want to inhale r134 via a heat source (eg a cigarette) it does something nasty, not sure its just carcinogenic I seem to remember there is other risks. This seems to suggest its poisonous in that state > https://www.hella.com/techworld/uk/Technical/Car-air-conditioning/Car-refrigerant-oil-filling-quantities-2114/#

That's me buggered then lol!

I do have a car here with charged AC system that will be scrapped at some point so could make sense to do as you say with the pipe between cars, I plan on cutting some AC pipe from it to practise brazing with. Still I suppose I'd need to make up the line to connect cars and the AC system on the car to be repaired will be open to the elements when I remove the pipe to fix it. How did you make the line Bri and does it run between low pressure ports or high to low port?

Thanks for replies. I probably won't connect another cars's AC system to this car's, don't have a vehicle with a running engine (to run compressor) to scrap and depleting a good car's AC charge defeats the object when could just put a partial charge in from a Halfords bottle without having to buy/make a long line. Something to remember though and I'll probably try this sometime in future in a different situation.

I saw some other videos on Youtube that make brazing the AC pipes look similarly easy as in the MachineMart video but on thin AC pipes, the surface tension of the melted rods almost magically spanning and filling holes without filling the pipe with braze... which is what I'd need because the pipe I need to fix has another pipe running inside it (visibly one pipe runs to rear AC because the second pipe runs inside it), don't want to fill the void between interior and exterior pipes.

Started with doubts about how well a brazed repair would hold, then on how difficult it would be to do the job (skill). The videos made me more confident in both respects, now still confident on braze effectiveness but a bit less confident in terms of skill, Clive's points agreed with my initial doubts. I will be trying it and if I can't fix the pipe could maybe lower ambition and braze the inny-outy pipe shut so at least the front AC will work or increase ambition and run two pipes to a different rear evaporator. Seen some videos where they make brazing fittings (such as for crimping rubber AC pipes to) onto AC pipes look even easier than repairing holes..

Different connections, also I think R134 has a higher working pressure than propane or R12 systems so an R134 system might not work on propane even if the seals don't fail?

Seals failing are reason I now won't pressure test with LPG... I'm surprised I was lax on that, thanks!

Still the hypothetical scenario where someone turns up at an AC shop with a none working R132 system full of LPG... Must have happened to someone, I was considering taking the AC fill pipe off the Halfords kit and connecting to an LPG source to pressure test, others will have read a bit on the net about some AC systems using propane and thought of chancing filling their system from a Calor bottle (maybe not to leak test but to recharge). What happens regards the AC machine and if the machine is broken what are the AC mans options (machine warranty, recourse on vehicle owner, etc)? I know machines recycle the gas and oil that they extract, does this mean they pump it into someone else's car or store it to send off for recycling?

Besides flammable, aren't some AC gases carcinogens if they come into contact with a flame or UV?

How do you know what's floating around in any aircon system though? Must be a few people that have read on the net that propane can be used in some aircon systems and tried filling R134 systems with it.

Another reason for thinking of using CO2 or LPG is that my large compressor broke years ago and I never bothered fixing it, started preferring electric tools rather than pneumatic for LPG work.

Yeh and I suppose there'll be a bit of water vapour in there now anyway with it having the leak low down under the back of the car. Can't be a massive leak, I got the aircon working for a few minutes just using a Halfords recharge kit but knew it was going to fail when she heard the hissing (better hearing than mine, 10 years younger + didn't spend 20 years DJing).

Have to wonder what effect LPG or CO2 would have on their machine... imagine them assuming it'll just have R132 and air in there until smoke starts pouring out of the machine lol, don't see it being a problem but can't be sure, or may be a problem when they come to recycle the gas... although nitrogen can't be a problem.

Do you reckon the DIY head repair would work using this stuff?

See the video on the this page https://www.machinemart.co.uk/p/aluminium-repair-starter-kit/

Fix your own aluminium cylinder head where pitted on the compression gasket land due to a blown head gasket / easily fix holed aircon pipes? Would you have faith this would work?

I have a leaky aircon pipe (not on a P38), haven't looked where the leak is yet but the missus could hear it was near the back wheel. When I get time plan is to pressurise the AC system (with CO2 or LPG because DIY AC gas refills are expensive, I don't have nitrogen and don't want to shove water vapour in with compressed air), locate the leak, remove pipe and hopefully use this stuff (cheaper from Ebay) to braze and fix it. If that works I might let an AC firm suck all the gas out and refill... but wonder if it CO2 / LPG would be a problem for their machine?

Gilbertd wrote:

Nice job but one thought occurs. Why didn't you run the wiring to the tank in at the same time as the pipe? Now you've got to grovel under the car again, with the associated crap in the eyes, to do that.

On most vehicles including P38s I just tape wires to end of pipe before routing pipe. When pipe is routed I tie wires to pipe as I fix pipe with pclips. Had more than enough crap in my eyes for 20 lifetimes! Can't do it on all models of vehicle but can on most, especially easy ones like P38s ;-)