Aircon Woes

If you have seen my post in the C3 Area you will know I am having air conditioning troubles.
If you haven't I'll recap. About a week ago the aircon in my car just stopped working, literally over night. I checked the usual suspects, the joints and compressor, for oil leaks...nothing. I replaced the ECU (I have two identical C3's...that story is in the C3 area too) no change. Went over all the lines for oil leaks, still nothing. WTF? There should be an oil leak if refrigerant is leaking out! With very slow leaks you might not see the oil but this failed over night. Being second hand and not knowing the history of the car I assumed there was no oil in the system and hence no leak (well, it's all I've got to go on). The only way to determining the actual amount of oil in the system is to pull every part out and drain it. I wasn't doing that! The entire system takes 135mls of oil and 80 sits in the compressor. Not enough oil in the system and the compressor is not correctly lubricated. Too much, and the oil displaces refrigerant and the system is inefficient. You also risk a compressor lock up. So I put 80mls in, to err on the side of caution . Sealed the system up, vac'ed it down, and add just enough refrigerant to get the compressor running. Sure enough the leak showed itself! This time oil did come out. As the pictures show the low pressure line had been rubbing on the engine mount and caused a pin hole.
I will need to repair the hole. Should be able to Aluminium braze it if I remove the engine mount.
Anyway, I thought people might want to check their aircon lines to see if they are rubbing and save themselves a lot of trouble.

I supported the engine and removed the R/H engine mount and shifted the expansion tank out of the way to expose the culprit.
What now? Repair or replace? Replacing it would be a pain and relatively expensive but repairing thin walled aluminium seemed like a job for experts. I could put fuel tubing and a hose clamp on it but that's too dodgy...even for me LOL. So it's off to the interweb to see what they say.
There were plenty of videos on Youtube showing repairs to aircon lines just like mine. I bought some of this "aluminium solder" from Ebay, tested it on a soft drink can...and it worked. It's important to note this rod is 90% zinc the remainder a mixture of copper and aluminium. It's melting point is approximately 380-420'C. However, unlike the Youtube videos this rod seemed to have an acid flux core which was marring the surface of the soft drink can, oh well small price to pay, I thought. I bought some thin zinc coated steel to act as a heat shield so I didn't damage the paintwork or any plastic parts, as you need to use a torch to heat the joint. This would prove to be serendipitous!!!! Long story short, because of the acid flux it ate away more of the hole and the "solder" simply flowed around the hole and did not "filet over" the hole like it did in the Youtube videos!!!!! Like any normal sane person, at this point, I FREAKED OUT! WTF! I work a lot with tin/lead solder and could see what was happening and this was not going to work. The acid flux was working too well. But one thing caught my eye, the zinc on the plated steel heat shield was melting and pooling. Of course! Euraka! Zinc sticks to zinc! I cut a patch out of the shield and soldered that to the pipe. It held a vacuum over night, so I was in business . Next up...re-gas.

OK. So I re-gassed the system and after nearly a week it still appears to be holding a charge (pressures look OK).
Aircon performance seems as good as it was before but ambient temperatures have only been in the low 30's.
A funny thing is the C3's aircon seems to perform better than my C2's but that's just a feeling, I have no empirical evidence of that. The two systems should be identical. If anything the C3 should perform worse, with a bigger internal volume to cool and all that glass (it has a sunroof).
Anyway, I can now drive my C3 around without sweltering in the heat.