I have to ask. What's the technical reason for having the high side hooked up when vacuuming? Doesn't the TXV always always stay slightly open? If so, that would let the pressure equalize on both sides of the system. (Not trying to argue, I just am trying to learn if I'm misunderstanding how the system works)
I honestly don't remember how we vacuumed it last time, that was ~2 months ago.
I'll probably miss a step trying to go through this..
- Vacuum system 30 minutes or more (low & high side open), check that it holds for at least 30 minutes.
- Fill system with Nitrogen - check for leaks with soapy water, make sure it holds same pressure for several hours.
- Vacuum system for 1hr, check again that it holds.
EDIT
- Close low side line, leave high side line open
- Purge lines (my manifold has a shraeder valve on the yellow line)
- Add first can with engine off, can upside down (using 12oz cans of r134a) into the high side of the system, working slowly
- Close high side line.
- Check for leaks with HF leak tester (can't hurt to look)
- Run engine - 18" high power fan pointed at radiators, auxilliary fan jumped to run full time.
END EDIT
- Turn off car.
- Check for leaks with UV light, soapy water
- Disconnect can
- Hook up fresh can
- Purge lines again
- Add second can, vapor only, can partially submerged in warm water. Watch pressures
- Repeat for third can.
- 4th can should be a partial fill to get proper pressures. (believe I figured ~37oz to get to 80% fill, may be slightly different since I have oversized condenser.
Any tips?
Probably going to try to take the vacuum pump back. Want to run one more test to make sure it can't achieve proper vacuum before I do. I think it's still under the 90 day warrantee.