I had a small tire to fill and used the pump on an empty "Slime" tank I had. I have the adapter but just removed the hose at the tire stem to relieve pressure.
For normal work with the adapter, I have a little clear water 120v pump (regular water hose fittings) I bought from HF years ago. Rated at 30 psi with no suction head....meaning with no attempt to lift fluid like in a well pump. I have used AF and WWFluid which is cheaper. Just stick the suction hose in the bottle and suck till dry, bleed air every gallon.
A word of caution here. Filled tires can be a problem on tire to rim seals on new, shiny-painted wheels at low tire pressures (<= 10 psig). If running very low pressures for a soft ride your best bet would be wheel weights. I thought I wanted to fill my 2400s tires and found out what I posted above. Any fluid in the tire helps it to slip on the rim under traction besides the weight can cause separation and fluid loss when hitting a bump. BTDT. Fluid is currently out and wheel weights are installed. Lot more bucks but works and my back is much happier.......
I mean, you have 2 tires rated for 2600+# each @ 30 psig (12 x 16.5, 6 ply, Industrials....known for stiff sidewalls) on a 1800#+ tractor and on anything but concrete or lush turf, what do you expect but a harsh ride. I finally got one but it took about $1,000 to get there....air seat (12v compressor and air bag) and turf tires but even at that the turfs 33x12.5x16.5 4 ply are rated at the same capacity (but i run them around 6-8 psig) and they also have stiff sidewalls. I'm thinking the 16.5" rim vs a 16" rim places the tires in a heavy duty environment when you look at what kind of equipment uses the 16.5 wheel. Well I'm not in a heavy duty environment and don't need the protection!