Hello, I just fixed the gap in the compressor clutch on my 2000 s70 and now it is cycling very frequently (2-3 sec.) I tried to put put freon in, but the pressure gets too high and when the clutch kicks on the pressures dips down drastically. I tried to only introduce freon when the clutch is engaged ONLY and then it started to stay on for longer periods of time until finally after continuing that process, it stayed on fully and the ac was blowing ice cold. I then shut the ac off and checked the pressure and it was through the roof. What do I need to do. I am confused with all of this. Thanks

 

Its quite possible you may have overcharged your system and the high pressure sensor is cycling the compressor. Also keep in mind that your target full charge PSI will vary based on air temperature ie on the order of 40 PSI on a cold day, 50-55 PSI on the LOW port with the compressor running. If you tap the port and read with the engine off, you will get a false, higher pressure reading than normal since the high and low pressures are balanced. So, get an AC pressure gauge, tap into the low pressure port. Set the AC on full chill/recycle air on, blower on 3 or so and start the car. bump the idle a bit and watch the gauge. If when cycling it stays higher than 55, you are over charged and you need to vent some of the refrigerant. To figure out the correct full charge PSI you need a chart for pressure at ambient temperature... Oh and word of caution, don't just vent like you are letting air out of a tire. The freon coming out will be extremely cold and can cause frostbite if it hits exposed skin.

 

There's a reason shops have specialised equipment to recover and charge AC systems. Have it properly evacuated, vacuumed and recharged with dye.

 

Also keep in mind that you don't have a target for pressure with the system off. If it blows cold and runs great, you check the pressure when it's running. Nobody is telling you it it's supposed to look the same when it's off. That's not so. It sounds to me like you may be just fine, just based on what you typed.

It's a shame these cars don't have high side pressure ports.

 

Great! Thanks so much!

 

Thanks alot!

 

Well, I ended up just continuing my process after venting some off a little back to normal pressure and then only introducing freon when the clutch engaged. It stays on a little longer and the ac stays nice and cold without cuting in and out while driving. Seems the clutch gap fix worked and the freon amp up helped too. Thanks for your input everyone!