90 4Runnr A\C System

If you think the system may be low on freon then hook up a set of gauges and check the pressure first.

unless you have the guage setup, it's worth getting an evaluation. after all, you don't have to have it fixed where they do the diag.

diag.

I was thinking that was where I was headed. Just hate forking over money for a diagnosis then wind up doing the fix myself. Also its an R12 system so if there is\was a leak I'm screwed anyway. But w\ no gauges \etc guess I'm just stuck. Thanks for the reply dc

If you think it may be low on freon and not closing the pressure switch you can jumper the pressure switch for just a few seconds to verify your compressor clutch is engaging. Just don't run it like that long because if you are low on freon you may be low on oil compressor oil as well and that would cause significant damage to the compressor. You can do a lot of the preliminary checks yourself. Check most of the fittings and the compressor for wet oily areas, if you find any you will probably need to replace o-rings. If the compressor is oily and you can verify it isn't engine or power steering pump oil then it will need to be replaced or rebuilt. I'm not positive if the 22R compressor is the same as my 3VZ 91 Truck but if it is you can get them resealed for about $65.00. The was the price two years ago from AAPAK in Phoenix. The 90 4Runners has a recall on the expansion valve under the dash, you should check with the dealer and have them run your VIN. If that hasn't been done you may be able to get them to change it out and take care of testing the system at the same time. If the expansion valve is the culprit the entire job may be free. Another note, if the compressor needs to be resealed or you replace it, fill it with ESTER oil. Ester oil is compatible with all refrigerants just in case you ever decide to do a conversion. I run Freeze12 in my truck, its $8.00 a 12oz can. Doesn't work quite as well as R12 but I still get 38 degrees or so out of the vents here in Phoenix. R12 is still available for around $20 a 12oz can according to one of the suppliers here in Phoenix.

If that hasn't been done you may be able to get them to change it out and take care of testing the system at the same time. If the expansion valve is the culprit the entire job may be free.

replace it, fill it with ESTER oil. Ester oil is compatible with all refrigerants just in case you ever decide to do a conversion. I run Freeze12 in my truck, its $8.00 a 12oz can. Doesn't work quite as well as R12 but I still get 38 degrees or so out of the vents here in Phoenix. R12 is still available for around $20 a

Thanks for the extremly informative response. Where can I locate the pressure switch you mention. As I indicated in original post all I have for this vehicle is a Haynes manual & it isn't much help for trobleshooting the A\C system. I will contact a dealer regarding the expansion valve.. I really haven't seen any indication of oily leakage thats why I am leaning to the problem maybe just being electrical. Thanks again for the info. dc

Its spring time, everyone runs AC check specials. Spend the $29.99 and get it looked at.