Ok, I'm about ready to give up on my mechanic and I need to pick your brains as to what might be wrong. I drive a 1995 4Runner. My A/C started working sporadically the end of last summer and is still doing the same thing. It now seems to not work more often than it does. The coolant levels are fine. The pressure on the low side is around 100 psi and when it works it works excellent. My mechanic said that it could cost a couple thousand just to get it working properly but that is because they're not sure what's wrong. I'm taking it in again next week to let them do a more thourough inspection, but I would like some opinions/ advice if anyone has had a similar thing happen. Electrical problem? Compressor going out? Any opinions welcome as I am about to give up on my 4Runner. Too many things starting to go out. Thanks ahead of time.

 

Check the expansion valve and it's O-ring. I believe there was a recall/TSB about this. Mine went bad and did not loose any coolant acted EXACTLY like yours. Also-behind the glovebox is a $90.00 circuit board with the duty cycle/frequency control on it. These can go bad and cause this.

 

What am I looking at as far as cost is concerned for the expansion valve?

Thanks for responding.

 

I think it was like $200 to have it done at Toyota-But I think there was a recall on this! Ask about it or search the net for more info first. Plus refrigerant r12 or 134 they will try to sell you some but they can re-use the stuff in there.

 

Seems to me that 100 on the low side is kinda high. Overcharged will do what you describe. Just a wild guess.