92 4runner evaporator

I have a FSM for the 1991 4Runner. It says for "Removal of Cooling Unit":

Disconnect neg bat cable Discharge refrigeration system Disconnect suction tube from cooling unit outlet fitting Disconnect liquid tube from cooling unit inlet fitting Hint: Cap the open fittings immediatly to keep moisture out Remove grommets from inlet and outlet fittings

• the above is all stuff under the hood, the fittings are the ones going through the firewall.

Inside:

Remove glove box Disconnect connections Remove cooling unit (remove the 4 screws and 1 nut)

Disassembly of Cooling Unit:

Remove wire harness Remove lower and upper unit cases a. remove 3 clips b. remove 4 screws c. remove upper unit case d. remove thermister with thermister holder e. remove lower unit case

Then your pretty much left with the evaporator

So it looks like you won't have to remove the dash.

PM

NO - just the glove box and surround --- maybe 5 phillips and couple 10mm bolts. Check to see if it was cover by a SSC --- you'd get free replacemnt of the valve and freon refile. My '90 4Runner and 93 Camry were covered. Check

The expansion valve is covered - SSCP01 JUN 93 Campaign - A/C Expansion Valve if that is the problem.

The problem I'm having is there is a leak somewhere. I had it charged and the next day the freon was all gone. They put dye in it and said it's the evaporator that's leaking. I don't know how they can tell it's the evaporator since they didn't even remove the glove box. This was not a Toyota dealer. I'm hoping I can get a used evaporator and do a swap then take it in to be recharged. Hopefully, it's that simple.

If they check everywhere under the hood (the condenser core, the compressor gaskets, all the lines and hoses) with an electronic leak detector and get nothing, and sniff the dashboard ducts and the checker goes crazy, that's one good way to tell.

Another reliable check is to crawl underneath the car and find the oil charge and UV dye dripping from the AC condensate drain under the passenger floorboards.

The evaporator is aluminum tubing, and if someone in the history of the car ever tried to spray chlorine bleach (or another strong chemical not approved for the purpose) in there to cure an odor problem, it would eat a hole in the refrigerant lines in short order. No more freon, no more AC function, no more moisture, no more slime, no more odors - problem solved. (Of course, no odors, but no Air Conditioning either.)

That will work, but the shop will also need to change out the filter/drier (because the desiccant will be full of moisture from the air), properly evacuate and leak-test the system, and then recharge.

Be VERY careful and gentle while removing and reinstalling the connections on that core, with double flare wrenches (and remove the replacement core from the wrecked car yourself if you can) - that aluminum tubing will twist at the connection points very easily, and will work-harden and crack if you bend it back...

And make sure they check the oil level in the AC compressor, if all the oil leaked out and it runs dry the compressor won't last long.

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In case you didn"t know the expansion valve is connected to the evaporator core --- in plastic case behind glove box. The SSC was due to fact that something they put in the system corroded the valve so it either didnt let gas/fluid thru or it was released into the air. If you replace the core also replace the expansion valve. With the cost of R12 --- it might be worth taking to a dealer with hopes that it is indeed just the valve.

Yes, this stuff is beyond my capabilities. I'll most likely have another shop look at it. Thanks for your replies. This group rocks!

Listen to what people are telling you:

TAKE IT TO THE TOYOTA DEALER!!! Chances are excellent that it's the expansion valve, and you'll get a nice, cold, working AC at no charge to you. I had forgotten about the recall (I got the notice around 1993 but my AC was working then). My local Toyota dealer did the repair on my '90 4Runner early last year, and it cost me nothing.

Thanks, but I had called Toyota Customer Service a few months back when the problem first occured hoping I could get it fixed this way and they told me their records show that the previous owner had already done the Expansion Valve repair in 1993. They said they can't do it twice. So I'm pretty much on my own with this one. Judging from past experiences with dealers I don't think it will be cheap to get this thing fixed at a Toyota Dealer.