Mechanical pipe joints

[davidchesson]

I have a problem with the air conditioning on my car in so far as there is a small leak to the high pressure liquid line to the evaporator. The pipe is of course aluminium and the leak is in an area of the engine bay that is difficult to access. It would be even harder to replace the pipe as one clamp has very cleverly been secured from below before the engine and its crossmember were fitted, thus seemingly making it an engine-out job! As I can access the ends, albeit with difficulty, what are the chances I could replace the middle section with copper using either flare joints or compression joints? Would I be likely to get leaks, is the aluminium too soft or might I get corrosion over time? Your thoughts / experiences would be gratefully received.

David

[andy bailess]

I hate to say it as a fridge guy, but pop to halfords they sell leak prevention fluid which when added to the system will stop small leaks.I would advise you to pay the halford guys than do it yourself.

[Brian_UK]

Please cancel the leak sealer idea, no offence Andy:)

You could possibly make a flare joint on the Ali but it might well split during the flaring process.

Try a good, independent, vehicle a/c firm, or one man band, to see if you can get a high pressure hose assembly made up to replace the damaged solid pipework.

[frank]

I been told that Pirtek are able to make the hoses/ hose tube joints http://www.pirtek.co.uk/site/Dynamic/templates/home_5.asp?lang=1&page=10

[seacold]

Hi I agree with Andy, pay them to put the leak fix in, hate it my self I prefer to replace the pipe but agree not an easy job on some cars, forget trying to fix your self and would only use sealant as a last resault the only real fix is a new pipe. so if it has to be removed to repair it your better putting a genuine on back on as R134a has a tendacey to find its way through the piping/tube joint over a period of time

[The MG Pony]

You can indeed flare aluminium but it is quite an Art, it took me a long time to manage to successfully flare 3/8th to 1/2, thats the good part you can flare it easily once you learn how to work the pressures.

Any Case, all ways ask how important it is to you, if it is important pay and have new tubes put in, if not then shoot in some leak seal or get flex pipes made up.

[andy bailess]

Hi I agree with Andy, pay them to put the leak fix in, hate it my self I prefer to replace the pipe but agree not an easy job on some cars, forget trying to fix your self and would only use sealant as a last resault the only real fix is a new pipe. so if it has to be removed to repair it your better putting a genuine on back on as R134a has a tendacey to find its way through the piping/tube joint over a period of time

thanks for your support seacold:)

[davidchesson]

Thanks for all your comments from which it sounds like the flare joint route would be rather risky. The system did have some leak sealant in it but it didn't do the job (high pressure I guess is the problem) so I had decided the only way was for a replacement pipe. There is a scrapyard close by that has a car with what looks like a good pipe so I must just go down that route and remove whatever it takes to replace it.
By the way, has anyone opened up a compressor from a system that has had leak sealant in it? I did the other week, on a different car, and the chambers were solid with a clear gel that I assume to have been this stuff - not a good idea I think!

David