What size airline for tires?

bigger air line only gives you a little bit more air supply in your situation. IT will not fill your tires faster. You are bottle necked by your chuck. You wont be doing anything. Bigger hose with more volume only does justice when running big air tools with bigger fittings. So like i siad, with a air chuck and little air stem, you arent doing anything

 

You could always use 3/8 high flow fittings. No law says you have to use the standard home/shop 1/4 fittings.

 

Most chucks are 1/4 tread but they make the 1/4 tread 3/8 fittings to work for that. The one on the left side of pic is just that. Most 3/8 hose are 1/4 tread and 1/2 hose is 3/8 tread anyway.

 

Never seen a high flow chuck. Like kemosabi says. Get a good one that stays in the valve stem by itself. That's half the battle. If it's your trailer put a fitting on one of the air tanks. That way the hose will reach further. The old style red hose that doesn't get stiff in the winter is a must have. A valve off the dry tank on your tractor is way nicer too.

 

Friend of mine made a hose that clips on to both tires in a dual and the air chuck on the main hose clips onto that one in the middle. It airs up both tires at the same time to the exact same pressure. It takes a little longer with the engine compressor and works better with a shop compressor but It’s a cool deal. I’ve got the crossfires on all my stuff so I don’t need that cool invention.

 

Only reason I use 1/2 is with otherwise stick with 3/8 A cheaper B easier to handle