JimInVirginia

From my past experience, typical a/c work that requires a recharge will require not only the expansion valve and freon, but a new receiver/dryer. And of course enough money to keep the dealer in business. A do-it-yourselfer can quickly cap the receiver/dryer & reuse if the system hasn't been opened to the atmosphere. But it takes a vacuum pump to remove all air from the system before recharge. An old refrigerator compressor works great for that, fitted with an a/c guage hose.

Another member reported to me w/private msg that the problem I describe is common with the ES, and the expansion valve is the suspect. With temps in the low to mid 70's today, my a/c worked flawlessly, it seems. That would eliminate particles clogging things up because it wouldn't make sense that the clog unclogs for beautiful weather! Whatever is wrong can't stand a heavy load, & I don't know if there is any other component, other than sensors that read ok on the codes, that could fail under load. I assume pressure from the compressor is regulated to stay about the same whether weather is warm or hot, so I don't think compressor is my problem. Anyone else advise?

I have similar problem: My 1995 ES300 80,000 mi recently developed an air conditioning problem, having no a/c work done prior. The a/c works fine on days when the temperature is in the 70’s, producing output temperatures of 43 degrees at the dash. On very hot days (90’s out, 125 degrees in car after sitting in the sun, and high humidity), the a/c works immediately when turned on, dropping to 58-75 degrees quickly, but after a few minutes, the temperature stops dropping and begins to slowly rise until it is hotter than the air outside. I’ve disconnected & plugged the heater hose to rule out a water control problem. The a/c test codes come up 00, normal, except when in garage 21, which is normal for a darker area. Sometimes it works ok even on a moderately hot day, but most of the time not. This problem came on suddenly. The shop didn’t get to it until a cool day when it worked fine and said the pressures were ok. I’ve observed the compressor clutch and find that it works when in this failure-to-cool mode. Most of the times the sight glass is clear (is this normal for 134a?). Any ideas what else I can check before taking it back to the shop? I’d like to know the problem before they start changing parts at my expense! I’ve done my own a/c work in the past, but no longer have a vacuum pump. Jim