Sage advice requested from the A/C gods

[Dammitboy]

Hello, here's my dilemma.

92' Nissan 240sx

Remanufactured compressor, new filter dryer, new expansion valve, new o-rings.

All fittings were lubricated with ester oil, threaded correctly & torqued to FSM specs. Pulled 28mm of vac for 30 mins. & it held it for 30 mins.

Recharged with r-134a, got vent outlet temp of 38 degrees, but noticed the evaporator drainage was milky, like skim milk. So, I did confirm the leak was from 2 joints in the expansion valve, removed the evap, replaced the o-rings, torqued correctly.

This time to be safe, I pressure tested the evap. with 75 pounds of air pressure under water with the expansion valve in place, NO leaks.

Reinstalled the evap, & guess what? Still leaks!!! What the hell am I doing wrong?

Please advise.

Kevin


Modified by Dammitboy at 11:19 AM 8/11/2006

[AZhitman]

Wait, you're basing the existence of a leak on the presence of evap drainage?

Unless I'm missing something, it sounds like your A/C system is working fine, holding pressure, but you have some funky comtamination of the evap discharge...

Hell, that could simply be a clogged or dirty drain line.

[Dammitboy]

Hey AZ,

Well, I wish that was all it was. When I redid my A/C, I throughly cleaned the lines, condenser, evaporator & inside of the evaporator box, as it was full of crud.

I took a sample of this milky drainage & it did have oil in it. I reconfirmed it was compressor oil when I put in dye & found it in the evap drainage. Consequently I'm losing pressure also.

For some reason, it is coming from the expansion valve. There are 3 joints on the exp. valve, but 2 are leaking. Like I said earlier, this is my 2nd time around trying to seal it up, I'm starting to wonder if there's a trick to doing this.

[benemorius]

There's no special trick. Be sure the o-rings are big enough to get a good seal and be sure you get the fittings tight enough. If you're going to pressure test it before reinstalling it, do so at the highest pressure you can - up to 400psi.