H1
That's right, the Hummer has CTIS (Central Tire Inflation System) that allows you to inflate or deflate the tires from inside the cab. The system runs on front only, rear only or both. So if you see both rear or front tires flat like that the guy probably has a leak in the system; which is very, very common!
Here's mine as it sits; I haven't drove it for a couple weeks now with the Pcar on the road and the front system has a very minor leak somewhere among the miles of air lines and fittings; I'm putting an air cock valve on each tire to prevent this, as the search for air leaks is endless; you get them all for a couple weeks and then one off road trip and bang, flat tires the next day.
Good news is that It only takes a few minutes and they're right back to full pressure again; what'ya gonna do?
