Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
Hi,Unfortunately there is no real way to properly fix these condensers when they leak other than to replace them.
The point of leaking is at an extremely thin bar/channel that attaches to the end tank... any attempt at soldering or welding this is rarely successful without causing further damage.
Trying to puddy it shut (like with JB Weld or similar gimmicks) will be unsuccessful as this area of the condenser see pressures in excess of 350 psi regularly.
Liquid sealers (like are injected into the gas) will slow it down, however in the long term they will cause increased wear on your compressor (A much more expensive problem to fix) and depending on what sort of coagulant is used can cause the expansion valve to jam (as its orifice is smaller than the leak).
You could try finding a radiator shop that might want to try fixing it, but when you consider similar repairs on a radiator are usually in the $100-150 range and you can get an aftermarket condenser for around $50 online, it really makes little sense to even attempt it. Replacement is the way to go here. It is not just the best solution, realistically it is the least expensive if you go with an aftermarket condenser too.