Help. My AC in my V70 doesn't blow cold air. Low-side pressure varies from slightly below 20 to 45. The compressor runs for about 2 seconds and then goes off for about 6 seconds. I shorted out the low-side pressure switch to keep the compressor engaged for 20-30 seconds and the pressure dropped to below 5 (the air was still warmish). The high side line going into the firewall was cool and the low side line was warm. My question, does the system need more R134a, I'm unsure.

Thanks for the help,

John R

1998 V70 1994 850

Man, I had two paragraphs typed and then lost it!
Read this site:
http://au.geocities.com/ozbrick850/aircon-keithP.html

Remember that two cans or r134a will fill your system. Go ahead and use leak stoppers. Oil will not evaporate until the pressure is zero and outside air has entered your system.

Klaus
--
98 V70Rawd(108Kmi), 95 854T(88K mi), 75 164E(173K mi)

I read the essay on A/C, it's excellent. I'm going to add R134a with the oil and leak stoppers, since the piercing valve in my kit can't start on the 'straight' R134a. Thanks for all the help.

Cheers

John

You will need to know the high side pressure to determine more of what is going on. It soulds like this is something that you may mot be comfotable with. If so get qualified help as you can get hurt fooling with this stuff.

Probably. It coud also be someting else such as problem with the expansion valve. If you have lost that much 134a then you need to find the source of the leak. Also you will have lost refrigerant oil as well and will need to replace that. With a major leak you will get air into the system and will need to evacuate the system and recharge. Good luck

Thanks for the advice. The kit I bought contains the R134a mixed with oil and a leak stopper and I also bought several cans of R134a and one can of lubricating oil. Hopefully this will do the trick.

One question, I have seen in the threads that some suggest not using a leak stopper when recharging since it may make the system more difficult to work on by mechanics. Based on this, I'm wondering if I should use the straight R134a and then add the oil separtely rather than using the can with them and the leak sealer together.

Do you have any thoughts on this?

Thanks again,

JohnR.

Thanks for the advice. The kit I bought contains the R134a mixed with oil and a leak stopper and I also bought several cans of R134a and one can of lubricating oil. Hopefully this will do the trick.

One question, I have seen in the threads that some suggest not using a leak stopper when recharging since it may make the system more difficult to work on by mechanics. Based on this, I'm wondering if I should use the straight R134a and then add the oil separtely rather than using the can with them and the leak sealer together.

Do you have any thoughts on this?

Thanks again,

JohnR.