DK Audio

The AC in my 98 does not work, the air blows the same temperature as it is outside. Checked all fuses, I believe the compressor doesn't turn on, which will happen if pressure is too low. I started to unscrew the Low side cap (behind the engine by the firewall, the cap has an "L" on it) and I heard some air leaking. I screwed the cap back in...a few minutes later I unscrewed it all the way and heard more air leak and then a little pop (like the valve was stuck and was just put back, it sounded the same as when you fill your tires with air and then pull the compressor hose from the schrader valve). Therefore, I think the leak was just in the valve for the low side. I found the High side (in front of the radiator) and it is missing the cap comletely. I also noticed a little viewing window with what appears to be oil inside, what for?

It looked like the valves can just be replaced and they are threaded, is this correct? My plan was to replace both valves and then recharge the system, does that sound reasonable and possibly where the leak was?

What is the procedure to recharge the system?

Thanks

DK Audio

Still looking for help on this one...
Bump

Kansas

Put in dye, recharge the system and then check for a leak. Guessing can get expensive. The leak could be in a number of places. I had a slow refrigerant leak in the A/C system of my similar 2000 LS400 for almost two years before it got bad enough for my long term Lexus trained mechanic to find it -- and the leak wasn't in either of the places you are looking at.

These systems have to be only slightly low in refrigerant to stop producing cold air. The viewing window has proven to be not all that accurate for telling when the refrigerant is too low -- it takes gauges to tell.

DK Audio

Sorry for the delay, I have some questions...
Don't you need to short two wires to get the compressor to turn on to take in the refrigerant? How do you know when it’s full and pull the can? I would love a tutorial but haven't found one. If there is no leak is the dye refrigerant ok to leave in there?

jerryparks

iTrader: (1)

My refrig. was low in my '92 LS 400. Friend added a can of 134a and so far, it appears to have corrected the problem. I would go to autozone or where ever
you deal on auto parts and have them go out and add a can of 134a and see if that cures your problem, and, also buy a cap to place on your high side line. Dirt can accumulate there and case problems in your system by drawing dirt and grime into your system when you add 134a. If you have autozone add
the 134a, be sure and check the area in and around where the cap goes
to eliminate the above potential problem.