How do you recharge the HP side of the AC?

[hawkeye18]

As the subject says, how does one go about pressurizing the high pressure side of the AC? I assume the store-bought cans of AC refrigerant aren't going to work at all, for many (duh) obvious reasons, but would I have to take it to a shop? I really don't want to have to do that... TIA for any replies...

 

[Ishodu]

You don't add it there! Why do you want to do this? If you can't get it in the low pressure side just remove the low pressure switch near the coolant reservoir and jumper the female end of the plug to start the compressor and this will make the low pressure side low enough to let in refrigerant.

 

[Bill Strobel]

You always charge from the low side. The high side is just used for gauge readings. The easiest way to determine the low side is it is always the one closest to the evaporator (inside the heater core). If you do not have gauges you can use a vent thermometer ($4 at any parts store) and keep adding refrigerant a little at a time till you get the coldest reading from the vent. You can then adjust the low pressure switch (on top of the accumulator) by removing the wire looking in the bottom of the switch and turning the screw in 1/8 turn increments (ccw) and then driving the car with the thermometer still in the vents and observing the temp. 2-3 miles ought to do it. Keep driving and adjusting the switch till you get the coldest air out the vent. Do not go to far or the evap will freeze solid and no air will blow. Anything 38-40 degrees is ideal on a hot day.

 

[hawkeye18]

Thanks for all the replies, it turns out that the system was just so devoid of refrigerant that I couldn't get the compressor to stay on long enough to charge it. I jumpered the plug on top of the dryer/accumulator and that kept it on.. 34 oz of refrigerant later, it was filled. I somewhat suspect a leak... (duh)