Compressed air to drain Coolant - Genius or Idiot?

I’m draining my coolant @100k, drained radiator, then trained another gallon from the passenger side pet cock. Drivers side (yes there’s a drivers side) is super tough to get to though. So here was my idea which ended up working extremely well: I adjusted my air compressor all the way down to around 15 psi. Then I pressured the overflow, just used my hand over the overflow cap, with the radiator cap on tight, and a slight pressure in the system, the rest of the engine block drained back into the radiator and then into the bucket. Anyone see any problems with this? Has anyone else tried it?

 

With your pressure low you should be fine

Keep it as close to the radiator cap pressure then you will never hurt anything.

 

That was my thinking, sure was a lot easier than getting a socket on the drive's side drain.

 

Where people blow things up is using Shop Air at @ 90 psi or water at 50 to 60 pounds PSI in older cooling systems

Old clogged heater cores and radiators love to fail.

 

Lol just use a long extension (e.g. ) and go through the wheelwell.