Need AC Charging Troubleshooting Assistance
Thread Starter
Instructor
Joined: Mar 2003
Posts: 203
Likes: 31
From: Baltimore MD
Need AC Charging Troubleshooting Assistance
My AC quit working so I bought gauges and started troubleshooting. The pressures were too low for the compressor to kick in, so I added a can of freon with dye. The pressures went up high enough with the one can that the compressor ran. I could not find any leaks. After a week, the pressures were low. There was lots of dye around both service ports, so I replaced both schrader valves. I bought a vacuum pump, and drew a 26 in / hg vacuum. I then shut both of the gauge valves and the vacuum held, so I figured the schrader valves were the cause.
I replaced the accumulator and drew a vacuum of 26 in / hg for 6 hours. I closed the gauge valves, attached a can of freon, purged the yellow hose, and turned on the low side. It drew only a little freon, went to 10 psi and then stopped drawing freon. The high side is still showing a vacuum.
One note: the vacuum gets to 26 in / hg very quickly. Am I measuring the vacuum in the hoses only because I am not tapped into the AC system. Should it take some time to reach 26 in / hg. Its a 1.5 cfm single stage pump. I have the automatic couplers
This feels like a coupler issue at the service ports. Worked initially, changed valves, not working. Not sure what I could have done wrong with the installation of the valves.
I replaced the accumulator and drew a vacuum of 26 in / hg for 6 hours. I closed the gauge valves, attached a can of freon, purged the yellow hose, and turned on the low side. It drew only a little freon, went to 10 psi and then stopped drawing freon. The high side is still showing a vacuum.
One note: the vacuum gets to 26 in / hg very quickly. Am I measuring the vacuum in the hoses only because I am not tapped into the AC system. Should it take some time to reach 26 in / hg. Its a 1.5 cfm single stage pump. I have the automatic couplers
This feels like a coupler issue at the service ports. Worked initially, changed valves, not working. Not sure what I could have done wrong with the installation of the valves.
Last edited by fmvette9; Aug 18, 2015 at 08:13 PM.
Le Mans Master
Joined: Aug 2005
Posts: 5,375
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From: CA.
St. Jude Donor '13-'14-'15
I would try to bypass the coolant/freon switch on the dryer---Unplug the pigtail and fashion a piece of wire and temporarily connect both sides of the PIGTAIL with the wire--Then see if the A/C stays on all the time----If it does you may have a bad dryer or a bad coolant/Freon switch
