Lexus GX 2004-09 :: A/C System Stopped Cooling

Ok, a year or two ago, a small leak in our 04 GX470 prompted me to have an a/c guy recharge system (little did I know how easy it was to do). At the time, he used his blacklight (during the day) and "thought" the condenser might have a leak in it.

Fastforward to now, the system stopped cooling. There isn't any noise from the compressor and the clutch does seem to engage normally.

I went to Autozone and rented the DVD on A/C systems. Using the gauges, I found there was no pressure on the H or L sides. I replaced the condensor (a no brainer ... it even came filled with desiccant/drier though I had to return it since the condenser didn't have the plugs in place so the desiccant/drier would have likely been 'wet' already ... no problem). I noted a very slight grainy, metallic in the system, but not very significant ... I did not flush any hoses, but I did look at all visible hoses for dye stains.

I connected a vacuum pump and kept it a 30mm Hg vacuum for 30 min and rechecked it 30 min later to see that it held the vacuum. The first time, it didn't, so I rechecked my connections and repeated. It seemed to work. I charged the system with 24 oz (27-29 is capacity so I wasn't quite full) and the system was nice and cold.

Unfortunately, cool only lasted 3-1/2 days!

The original condenser plug (for the desiccant reservoir) was plastic or teflon, but the one that came with my replacement was Aluminum. A replacement desiccant bag also came with another plug (a plastic or teflon one), but it seemed to strip so I opted for the metal one anyway (besides, it had two green 'O' rings to just one 'O' ring for the plastic one.

Two days ago, I thought I'd got it to hold the vacuum in the system, recharged it again (I dried the desiccant bag in the oven for 5 hours at 175 deg F to make sure I'd gotten rid of any moisture that had developed).

Dog gone it, it's hot again! Looking at it with my black light at night, I do see dye (I'm using the yellow kind) at the L-side Schrader valve and on the plug to the desiccant compartment, but no where else. Where's the drip line for the condensate so I can check to see if there's a leak in the evaporator?

I tried wrapping some teflon tape around the metal plug for the desiccant/drier, but it still wouldn't hold a vacuum when I tried using the pump tonight.

I have another dessicant/drier bag and plug arriving tomorrow since I'm afraid that it still could just be leaking out the base of the condenser, but I'm not sure.