#1 |
I'm in the midst of converting my a/c from R-12 to R-134a. I have read and studied Matt St. Denis' how-to article found here, as well as the Haynes and Ford shop manuals. I've also combed through pages on the Internet.
The HR980 compressor locked up on the way to Tucson, AZ (about 100 miles away) in early June 2014. Needless to say, driving in the desert in the summer without a/c is really not acceptable, but so is working on the car in the heat...so I put it off until Thanksgiving.
Here's what's going on: I rounded up all the parts, tools and supplies I thought I would need (including manifold gauges, air compressor, vacuum pump). Replaced accumulator, liquid line (with orifice tube), and found a used compressor on eBay that was local (!!) and that I was able to examine and do some testing on before I bought it. Flushed out all the other parts, added POE oil and new green o-rings, bolted up and attached the compressor. I vacuumed the system down to around 29" Hg for 2 hours, after 1 hour it held steady--after 12 hours it had lost about 1 inch.
Started the recharge process...it took hours to get the first can of R-134a into the system (engine off), even while heating the freon can upside-down in a warm water bath. (The can was connected to the low side by the accumulator.) It was about 65 F that day in the shade...after about 7 hours I gave up, shut off the gauges and came back the next day.
Next day I got the second can started, decided to fire up the a/c (started the car). Closed the high side manifold valve, jumpered the clutch cycling switch connector wires so the clutch engaged, upped the RPMs to about 2000. It seemed to work, but sloooowwwwwlllly. The compressor was making that dull sound and the vibration that it makes when it's operating...but after a while I noticed it had stopped that. I disconnected the jumper wire, and the gauge readings did not change--about 120 on the low side, about 150 on the high side. Stopped and closed everything up to end the day.
Came back the next day, discovered I had lost all the (admittedly small) amount of freon I had gotten in there...removed the compressor. Attached high- and low-pressure lines to it, vacuumed just the compressor down to about 28 Hg for two hours--it held for an hour, then overnight.
Turning the compressor shaft by hand, I can feel good suction on the center port, and good air discharge on the exhaust port.
My questions are: Does it normally take this long to recharge the system? And, despite its apparent failure during this process, is the compressor at fault, or could something else be the culprit? There are no strange sounds or vibrations coming from it...it seems to be okay and I would trust it--except for that one occurrence.
Thanks in advance for your help.
The HR980 compressor locked up on the way to Tucson, AZ (about 100 miles away) in early June 2014. Needless to say, driving in the desert in the summer without a/c is really not acceptable, but so is working on the car in the heat...so I put it off until Thanksgiving.
Here's what's going on: I rounded up all the parts, tools and supplies I thought I would need (including manifold gauges, air compressor, vacuum pump). Replaced accumulator, liquid line (with orifice tube), and found a used compressor on eBay that was local (!!) and that I was able to examine and do some testing on before I bought it. Flushed out all the other parts, added POE oil and new green o-rings, bolted up and attached the compressor. I vacuumed the system down to around 29" Hg for 2 hours, after 1 hour it held steady--after 12 hours it had lost about 1 inch.
Started the recharge process...it took hours to get the first can of R-134a into the system (engine off), even while heating the freon can upside-down in a warm water bath. (The can was connected to the low side by the accumulator.) It was about 65 F that day in the shade...after about 7 hours I gave up, shut off the gauges and came back the next day.
Next day I got the second can started, decided to fire up the a/c (started the car). Closed the high side manifold valve, jumpered the clutch cycling switch connector wires so the clutch engaged, upped the RPMs to about 2000. It seemed to work, but sloooowwwwwlllly. The compressor was making that dull sound and the vibration that it makes when it's operating...but after a while I noticed it had stopped that. I disconnected the jumper wire, and the gauge readings did not change--about 120 on the low side, about 150 on the high side. Stopped and closed everything up to end the day.
Came back the next day, discovered I had lost all the (admittedly small) amount of freon I had gotten in there...removed the compressor. Attached high- and low-pressure lines to it, vacuumed just the compressor down to about 28 Hg for two hours--it held for an hour, then overnight.
Turning the compressor shaft by hand, I can feel good suction on the center port, and good air discharge on the exhaust port.
My questions are: Does it normally take this long to recharge the system? And, despite its apparent failure during this process, is the compressor at fault, or could something else be the culprit? There are no strange sounds or vibrations coming from it...it seems to be okay and I would trust it--except for that one occurrence.
Thanks in advance for your help.
Another proud dues-paying member.
1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 3 T5OD full rebuilds, 6 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 3 T5OD full rebuilds, 6 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....