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leak test advice

jdc25180 on Fri June 11, 2010 12:37 PM User is offline

Year: 2001
Make: lexus
Model: is300
Engine Size: 3
Refrigerant Type: r134a

I've recently replaced my compressor, evaporator, and condenser/dryer, flushed all the lines and replaced and oiled all o-rings. I tried doing a vacuum test, which turned out losing all of its vacuum in a matter of couple of minutes. I read that sometimes a vacuum test will lead to false results for leak tests so I added dry shop air (there is no 134 in the system) to 90 psi and let it sit overnight. I lost 1 psi in the last 12 hours. There are a couple of variables in this. Could the quick connect coupler be leaking, could the ambient temperature (probably 10 degrees cooler and its raining today) make that 1 psi difference. Soapy water didnt turn up anything which I didnt think it would with that slow of a leak.

Should I just vacuum overnight, then charge up with 134a and then take it to a shop with a detector to find the leak. I am just nervous about putting my dash all back together and not finding the leak under the hood. The only thing that I could see leaking would be the low and high side rubber hoses and they run about 175 a piece.

Any advice is appreciated.

TRB on Fri June 11, 2010 6:12 PM User is offlineView users profile

Judgment call here. If all the connections show no sign of a leak and you only lost 1 psi over a 24 period next step is to charge it and do a final leak check.


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