My Citroen XM 3.0 PR-Vestige

[Dean]

Indeed you can but system pressure is relative to some degree to the gas you use, what you really need though is oil weights, there should be a chart that shows how much oil sits in each component so after you have swapped said component you know how much you have lost, that's really why I've got to flush mine, I have no idea what oil is in it and how much since the drier will need changing and its had a new condenser, to much oil and the pump gets slugged, too little and, well.
Gassing actually looks fairly straight forward if you know what to do and what sort of pressures to be running at and what faults cause which pressure readings on which side of the system.

My charge/diagnostic manifold was £20, gas is £15/6oz oil is stuff all, the most expensive bit to squire is a VAC pump to do the job, they can be had for £60 but I'm still hunting for something a little more economic.

D

[Dean]

Dean,

RS24 (R426A) does seem to get some good write-ups. It's also US EPA approved for retrofitting to R12 systems.

Try this for a listing of both R12 (and oil) and R134 (and oil) for all the XM models...
http://www.autototal.ro/dmdocuments/Cat ... 0Hella.pdf
Behr-Hella are pretty trustworthy.

C.

Thanks Chris

I've seen ac engineer forums say its "leaky" and doesn't hold too long (small molecules?) But they say that about 134 too so not sure how true it is, don't know what weight of charge it needs also which will effect pump loading.

D

[White Exec]

This site says that RS24 needs a charge weight of 40% of R134a, and 35% of R12...
http://www.duracool.com/-faq.html

[Dean]

Duracool is R12a (propane) RS24 is a mix of R134a, R125, Butane and some other things........apparently.

D

[White Exec]

Google "EPA R12a" for reasons not to use this refrigerant.

[Dean]

I found this? bit of good old conspiracy theory I know.
The EPA makes me giggle and be thankfully I don't live in the US, they banned the use of ozone depleting gasses (well done you) but somehow had a say in what the replacement should be which I find odd, some states in the US have banned hydrocarbon refrigerants, some have not. There is/was an argument running because the EPA were saying it was illegal to gas with hydrocarbon refridgerants when in fact in most of the US it was not, bit odd that.
Then we come to the subject of flammable gas as a whole and its use in cars, it is in a sealed system away from sources of exposed ignition, if it did find its way out, and all of it mixed just right with the air to give an explosion it would not be very impressive, a bath full of natural gas with a match thrown at it certainly scares the 1st year plumbing apprentices but that's it, its not very exciting twice, unless you find another bath bomb virgin first year (happy, happy days) and no we never done that in the project house at college, honest.
Anyway what I'm getting at is the EPA's ramblings are of no consequence, hydrocarbon refrigerants are not illegal here and so long as every camper van carries at least 13kg of butane or 11kg of propane around the country in no more than glorified plastic box without managing to bust into flames and inhialate entire sections of the new forest of lake district on a daily basis I'm sure I will be fine with 15oz nestling next to the 85lts of petrol pumped directly over the top of the engine in rubber pipes, I will try not to crash onto the Chevy corvette thing that drives around with twin 140ltr LPG tanks in the boot, that's 280ltrs @ 1.95ltrs/kg = 143kg of LPG gas which, even by my standards would be a pretty impressive pop, you would probably see the fireball from Le Havre on a clear night

D

[Dieselman]

Years ago my BIL performed a test that required long duration heat. 750 Gallons of petrol were pumped to keep the fire well stoked...

[White Exec]

Ok, the EPA may be corrupt, States have different laws (it's America, after all), and the amount of refrigerant gas is small, compared with what might be carried in an LPG vehicle tank or for leisure purposes.

BUT, and it's a BIG BUT. . . Gases carried in vehicle fuel tanks, and in cylinders for leisure purposes, are (a) in heavy pressure vessels, and (b) located in areas of the vehicle not prone to crash damage.

For AC, the AC radiator is decidedly up-front and vulnerable, and is highly likely to be ruptured in the event of a front-end shunt.

I speak from some experience here. Several years ago, while on Gibraltar, our Toyota RAV4 was front-end rammed by the vehicle in front (uncontrollably in reverse). The rad grille was pranged, as was the AC rad. This latter started spraying a white cloud of refrigerant straight forward, and continued doing this for several minutes. Had there also been a source of ignition, and had the refrigerant been flammable, this could have been extremely nasty. Front-end damage is not exactly uncommon.

I'm sure you're dead set on using propane, or something like it, and I've said my piece, and tried to point to some professional and authoritative info. I think you are unwise to go down this path, especially when workable alternatives exist. My biggest worry is that others may be tempted to follow. Sorry, Dean......nothing personal.

[russ92xmsed]

Well this is the latest sticker sample idea. Okay tech gurus.... correct the mistakes!

[Dean]

Nice work Russ, hope your having fun, swine!

This thread has been a bit silent recently due to nothing much happening, the abs issue was never resolved as it never happened again and is performing faultlessly as is the car.
There was an issue with an awefull rattly on the drivers side but other than doing the calliper bolts up there isn't anything to report.
Next stop is going to be my mates to get the teardrop roof trims re painted and I think the steering pinion is overtightened slightly so I've got to find the motivation to jack it up and crawl around underneath again but other than that it's rather boring really, just driving about in the sun and washing it.

Not the most exciting update in the world but not depressing either

D