Re: How and where to do an air pressure check
Welcome to iboats.
There should be a plug on top of each section of the the tubes, you need to pull those plugs and I have used a blower nozzle to get air in the them, just blast it wide open for 30 seconds or so then have a helper put there hand over the plug to hold the air in, you only need a few psi and never more than 5ish to much and you risk blowing the tubes up.
Once you have air in it spray everything you can get at with some soapy water,we use Polmolive dish soap at work (Bennington) and it works really well, then just look for bubbles.
you should check everything but especially the back of the back brackets and the front of the front brackets, this is a stress point and is prone to crack.
You don't actually keep air in the tubes although some boats do have air fittings and no, it won't help them float any better with air in them, it just doesn't work that way.
Hope that helps.