chungmeow

My 99 gs400 is currently undergoing an evap replacement and is completely bare. I followed the following DIY: https://www.clublexus.com/forums/gs-...iy-w-pics.html

I am planning on applying an a/c flush but wasn't entirely sure when it should be applied. I am replacing the following:

- evaporator
- expansion valve
- compressor
- condensor

Is an a/c flush required even when all these parts are being replaced? Can I simply apply compressed air through hoses?

kt636

I would definitely flush the hoses and the new part as well before assemble everything together. You would assume that new parts are clean but I've flush new condenser before and there was stuff coming out of it. It would only take an extra hour or so to flush everything and you will have a peace of mind that its clean and your new compressor would appreciate it as well.

chungmeow

thanks kt636, ill go ahead with the flush, compressed air and vaccum.

marshun

since youre replacing all of those, is the inside of your lines black? aka black death?

i had that last year. replaced everything. super sucky

chungmeow

Well... While I'm waiting on my condenser, I've continued to research my flushing concerns. Apparently flushing isn't necessarily required in all cases. I plan on flushing out the lines: condensor to heater core lines, compressor to expansion valve line and compressor to condensor lines.

Compressor went bad and having two previous owners that did not take care of this car what so ever, I assumed it was a good idea to replace everything in order to avoid any further complications. Note - I did not replace the heater core as it looked perfectly intact. I simply drained the existing coolant.