Automotive Air Conditioning Information Forum (Archives)

MC721 on Mon August 31, 2015 1:24 PM

Year: 1995
Make: Lexus
Model: GS300
Engine Size: 3.o
Refrigerant Type: R134
Country of Origin: United States

Hello AC forum members!

My wife has a 1995 Lexus GS300 with about 150,000 miles.

About 4 months ago, the A/C started to not cool as it should and over the course of about 3 weeks it gradually lost most of its charge.

I added 3 cans of refrigerant with no apparent issues and the system has been working fine.

About 3 weeks ago, it began loosing it's charge again.

Last week, shortly after I started the process of adding refrigerant, I detected the slight smell of refrigerant.

After some investigation, I found that the plastic valve on the charging hose had a crack just above where the refrigerant can screws into the hose valve.

I removed the hose and checked the A/C.

The compressor cycled off and on every 4-5 seconds. When the compressor clutch engaged, it made a (for lack of a better term) "farting" sound at the back side of the compressor, with visible gas coming from the back side of the compressor, until the clutch disengaged.

I didn't have a chance to do any more with it until yesterday.

Now, when the compressor clutch engages it makes no noise, or cold air, and still cycles every 4 to 5 seconds.

Is it possible that the crack in the refrigerant hose allowed air into the system along with the refrigerant, over-pressurizing the system and causing a leak in the compressor?

If so, would it most likely be leaking at one of the compressor seals, or where one of the A/C hose o-rings mates to the compressor?

Also - I have been told that some auto A/C compressors have a high pressure or pop-off valve on them in case of over pressurization. Does anyone know if this is the case with a 1995 Lexus GS300?

Any insight or suggestions would be greatly appreciated by my wife (We live in Florida).

Thanks!

BTW - I now have access to A/C manifold gauge set and vacuum pump.

Cussboy on Mon August 31, 2015 2:33 PM

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MC721BTW - I now have access to A/C manifold gauge set and vacuum pump.

That's good, because you're going to need those.


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Originally posted by: MC721
My wife has a 1995 Lexus GS300 with about 150,000 miles. About 4 months ago, the A/C started to not cool as it should and over the course of about 3 weeks it gradually lost most of its charge. I added 3 cans of refrigerant with no apparent issues and the system has been working fine. About 3 weeks ago, it began loosing it's charge again.

Your system has a rather large leak, lost most of its refrigerant and cooling ability in 3 weeks, twice. So don't worry about air or refrigerant charge right now, you need to find the leak, and repair that first. If you need to, have a GOOD AC shop find the leak for you. Typically a combination of looking for oily residue, soap bubbles, UV dye/light/glasses, and electronic sniffer are used for this. Adding refrigerant to a leaky system is frowned upon or against EPA regulations too (unless specifically in the process of finding a leak).

mk378 on Tue September 01, 2015 10:49 AM

Sounds like you overcharged it. Total capacity from completely empty is 30 oz, so you should not have added 3 cans in any case. A system will stop cooling long before it is completely empty.

Also make sure the condenser fans work. If the condenser overheats you will have an overpressure situation similar to overcharging, causing the compressor to cycle off on high pressure and/or pop the relief valve.

Like Cussboy said, you must find and repair the leak before doing anything else. Otherwise it is just going to keep leaking out. Never be tempted to use a "leak stop" product, they do not work and will cause severe problems.