RXstate

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 condensor 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 ingauge 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 dessicant/drier though I had to return it since the condensor didn't have the plugs in place so the dessicant/drier would have likely been 'wet' already ... no problem). I noted a very slight grainy, metalic 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 condensor plug (for the dessicant reservoir) was plastic or teflon, but the one that came with my replacement was Aluminum. A replacement dessicant 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 dessicant 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 Shrader valve and on the plug to the dessicant 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?

Does anyone have any other ideas? Did I mention that it's HOT in the Carolinas in late June ... and it's getting hotter really soon ... and my wife is driving my COOL car while I'm trying to figure out her's?

I tried wrapping some teflon tape around the metal plug for the dessicant/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 condensor, but I'm not sure.

mann777

I see what you have done, but one thing most important of all is you missed is you need to completely discharge the refrigerant. prior to the process which you have began.
First after the recharge, you need to check the pressure at both ends ( Hi & Lo) using the manifold guage set. Ensure you start the car and raise the RPM to 1500, Ensure the Blower speed control within is at HI and should be at RECIRC mode. And off course AC switch on. Doors fully closed. The normal reading should Low PX side should read somewhere between 0.15-0.25MPa and the high pressure side 1.37 - 1.57MPa. If you do not get this value, that means there is moisture within the refrigerant. Now I see you have replaced your OEM condensor, which does not need to be, only if the receiver os clogged, and you see condenssation on the Frost pipes, that is the sign to replace the condenser.
Just do checks on the Expansion Valve, the majority of the faults lies in these component as if there is leak within the valve or the compressor the vacuum begins to purge , you will on the sight glass lot of bubbles, then the air has entered the refrigerant. You need to check the compressor oil or see if they are dirty.
Hope this helps

zippymbr

If you are anywhere near Durham I can help.

RXstate

I'm in Charlotte, Zippy.

Ok, issues I've determined:

plug from Autozone condensor is POS (when you apply a vacuum to the system, it almost caves in and doesn't seal at all ... I suspect even the flan, ges where teflon meets metal won't touch, but you certainly can't get it tight enough to seal). Consequently, I've gone back to the alumuinum plug (has two o-rings and I've replaced one ... I might replace the other).

I had the system holding -27psi just fine last night and changed it with 24 oz R134a (capacity is 27-29 so I'm a little under) and I could see bubbles, but no oil through the site glass.

I suspect I've proven that the issue is the EXPANSION VALVE or the EVAPORATOR so I'm going to do the EXPANSION VALVE NEXT unless I feel I've got better advise from someone else on here.

One guy's video on YouTube showed that the Toyota's is right behind the glove box, but I saw another on here who wanted to dismantle the entire dash to get to it. Does anyone have the diagram that they could post or fax? I'm afraid my budget is getting blown!

mann777

Here is the TSB which has the exploded view of the A/C and the parts which are looking for. Hope this helps. Also the Expansion valve.

RXstate

In reading over the pdf, I notice so many unrelated things that it says to remove (e.g. like the condensor that I've already replaced) that I'm confused how to interpret this thing.

I've essentially decided to just start with the glove box removal (page 19 of 45, and anything else in the way like blower motor cover & motor), etc. I also noticed that it says to "cut the lower instrument panel safety pad with a hacksaw" (when I first read thru, I didn't want to do this, but I'd prefer this to taking off the entire dash (like jbw5485's post).

Do you know how much oil needs to be added when just the evaporator's being replaced? I used 2 ounces when I replaced the condenser (20% of the total oil volume since, from what I've read, that's about the amount needed).