Hi All,
Had the system gassed up two weeks ago and all the gas is gone.
They added a coloured tracer dye.
I'm going to have a look myself now for any sign of leaks before I take it back to them (it is the dealer ....).
To be sure that it is the evaporator, do I just eliminate leaks from everywhere else?
If they've put the dye in it, you'll be able to see it really clearly with a UV light (one of those little handheld ones you can buy for checking security markings work well). When mine was leaking and only lasting a month or so, it was coming out the bottom corner of the condenser, one of the hoses from the compressor and one of the alloy pipes had a pinhole in it.
If you can't find any trace of a leak... check the pipes where they run along the firewall. On my first P38, the larger pipe, where it was hard up against the foam and the pipe sweats when operating, had corroded enough to have pin hole leaks on the rear side. No sign of any leak until I had a nitrogen test done and covered everything with soapy water. Only found it by the tiniest amount of bubbling up - then pressed the foam back to reveal it was venting through it!
Worth checking that before assuming you have an evaporator leak and stripping the whole dash out... whoops.
The other possible hidden spot is the top left corner of the condenser under the slam panel - there is a lump of foam that is wedged between the panel and condenser, and it can hold water and corrode the corner badly.
Condensers tend to be vulnerable to flying stones and other FOD. Ask me how I know!
Just got a UV torch ....... what am looking for? Blobs, spray, streaks?
All of the above Spiggy! Plus drips, dribbles, bubbles etc. Basically all of the dye should be inside the system so any sign of it outside- that's where one (there may be more) of your leaks is. Best done in the dark as well as it's not quite as flourescent as you'd hope. Edit- fluorescent even. Flourescent is what you might find in a bakers!
So I have to go out after dark ........ ooooo
Should give your neighbours a laugh anyway, watching you peering around under the bonnet in the dark with a black light
Even better- get yourself some fluorescent face paint and scare the cr@p out of them :-)
If you can't find it, find a specialist who can fill the system up with nitrogen - this is better than assuming a system is okay because it holds vacuum for a little while, as it'll be under similar pressure to operating. Once under pressure, they'll check everywhere with soapy water for bubbles forming like you would on the EAS.
Like I said, check out the pipes that run along the firewall if you do this and press the foam away behind them.
A safety point, use the special yellow goggles when using a UV light.
Thanks, I didn't know that.