Yep, the AC will run great for about 1.5 hours, then stop blowing cold air. Park it, let it sit overnight and it will crank out cold air all over again. Kind of a bummer though....most of our trips are about 4 hours drive time. I thought the evaporator was icing up, but doesn't seem to be...it even does it in 10% humidity...same pattern.

Any ideas?

 

Sounds like the expansion valve is sticking. Common problem on Toyota's.

 

did you check the freon pressure? If it's low on freon it'll do that.

 

Where is the expansion valve?


As far as r135, it cools fine for about 1.5 hours. I can't imagine that it's low on R135, but I'll check.

 

Maybe you should try R134. If you can cool for 1.5 hours, it's probably fine. Put a thermometer in your duct vent and get on the Freeway. If you hit 46 degrees, then your freon is fine. Then it's expansion valve or .....I hate to think the compressor may be overheating and not able to do the job.

 

If it's low on freon, it'll freeze up the coils, the lower the pressure the colder the system, to a point of course, then a low pressure switch kicks in and shuts down the entire system. Usually you fill it to a given pressure to bring the temp up just above 32 degrees.

Try running the system for 15 minutes, then turn the AC off but let the fan run for 15 minutes. Keep repeating this process and see if the system continues to produce cool air.

 

This technique used to work, but not any more. It's starting to sound like it may be low on R134. I'll get it filled or buy the kit and do it myself. If it's low though, that means my system is no longer sealed and it's leaking out somewhere, which means replacing hoses and maybe the compressor.

 

Usually the "o"rings at the compressor are the first to start leaking, they do have the dye that you can add to your system to locate it.

 

good luck with the compressor hayduke, mine worked fine for the first month and a half. then it sort of slacked off and barely got cool. my mechanic checked it out and gave me the good news, compressor is leaking, old r12 setup and $700 to make everything good as new with the r134. i think i can live with the windows/sunroof open, i can do a lot of mods for $700.

lee

 

I bought the Castrol "EZ Fill and Power Booster" kit and a termometer and pressure guage. I'll get into it tonight, check it out and repost. Thanks!