Bad idea! There is still moisture in the air and lines.
Nitrogen bottle and kit for pressure testing auto AC systems
- Thread starter Snagglefoot
- Start date
I got him beat. I used a Bicycle Pump to find an AC leak! I added a desiccant dryer between the pump and lines and pumped the system to 80psi. Sprayed foamy water everywhere and found the leak! New dryer and it was working fine. For a few months.
So all I need is a nitrogen regulator and bottle? I can connect to the center hose of the gauge set and charge the system as if using a tank of freon? And if I test it to 200 psi, won't that damage the low gauge that maxes out at 120?
Don't hook the low side gauge up during the test
But wouldn't you want to test the compressor function while it's pressurized buy running it a few seconds to see the running pressures?
Not with nitrogen in it. It will build extreme pressure immediately as nitrogen can't be compressed at those pressures.
Chris - I was going to get a nitrogen tank at a local welding shop. Something around 40 cu ft. Would that be big enough for a few tests?
Anything I need to lookout for?
I need to find a new nitrogen bottle because the one I was given is very old and I doubt anyone will fill it. I already have the nitrogen regulator. I guess I need to call a local gas supplier to see if they will sell me a tank.
Ya It don't take much. Just be careful about over pressurizing a system. 200 psi is plenty.
Thanks, I got a regulator, which has compatible fittings. I’ll be careful with the pressure when I put it in use.
I pressurized the system and sprayed down the lines to check for leaks. Found the upper condenser fitting leaking,
I replaced the o-ring and pressurized it again to 175 psi at 7:30 pm yesterday with 76°F. Do I still have a leak or are these readings normal?
9:30 pm 72° 145 psi
11:00 pm 71° 145 psi
7:30 am 67° 140 psi
I can assume the overnight drop of 5 psi is from the drop in temperature. What about the 30 psi drop in the first 2 hours? Is that just the nitrogen migrating throughout the system?
I replaced the o-ring and pressurized it again to 175 psi at 7:30 pm yesterday with 76°F. Do I still have a leak or are these readings normal?
9:30 pm 72° 145 psi
11:00 pm 71° 145 psi
7:30 am 67° 140 psi
I can assume the overnight drop of 5 psi is from the drop in temperature. What about the 30 psi drop in the first 2 hours? Is that just the nitrogen migrating throughout the system?
