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Contact cleaner for a DIY evaporator flush

Posted: Tue May 26, 2020 12:28 pm
by Al9
Hi everyone. About to get a second hand evaporator for my car. Planning to keep it as a spare just in case something somehow goes wrong with the old one. It's a parallel flow Denso design, aluminum, typical of early 2000s Jap cars. Evaporator replacement looks really easy on my car. I'd like to flush any old oil out and then store it with the ports capped, but all i have at hand right now is a can of contact cleaner and a LPG gas duster can.

I've read my contact cleaner's SDS thoroughly and it appears to be about 60% isopropyl alcohol and 40% hexane. Should be a good evaporative flush solvent for PAG oil.

I'm planning about getting some contact cleaner inside a port and then pushing it out with the gas duster and catching the oil+contact cleaner in a container, both directions, then let a good flow of gas duster through and then let it dry.

Is this a feasible idea or should i better buy a proper evaporative AC flush agent? Is the isopropyl alcohol going to corrode the passages inside the evaporator even at room temperature? Thanks

Re: Contact cleaner for a DIY evaporator flush

Posted: Thu Jul 02, 2020 6:13 am
by Tim
I know it has been a while and sure you have solved the problem. Very early on when flushing was being more of a concern. We used off the self isopropyl alcohol. It's not the best and has a flammability issue but it worked.

Better option and not a bad choice if you don't do a/c for a living. ... wgun-25615 ... ased-17344

Note Supplies change brands on us at times. Keep that in mind with flush solvents.

Re: Contact cleaner for a DIY evaporator flush

Posted: Fri Jul 03, 2020 4:43 am
by Al9
Yeah, that makeshift flush did wonders. Can't seem to smell contact cleaner anymore when i blow gas duster through (managed to create adapters for the outlet and inlet), can't smell PAG oil anymore either and i also managed to flush it to the point that dye visibly stopped coming out (i think any leftover oil won't affect the system's oil balance at that point). Storing it sealed in case something goes wrong with the one on my car, lots of potholes around, but it looks like a really sturdy design anyway. Mainly needed a spare TXV for an upcoming compressor replacement since it came with one, but keeping a spare evap is still a nice thing, was really cheap too and doesn't seem to leak. Thanks for replying.