Only if it's designed to transport more than 15 persons (including the driver) or carrying a quantity of hazardous materials sufficient enough to require the display of placards under FMSCR regulations.
Only if it's a vehicle equipped with air brakes.
Only if you're operating it on a for-hire basis. For personal, recreational use, you do not.
Air brakes are entirely irrelevant as far as whether or not that vehicle needs a CDL is concerned. The only time you need a CDL to drive an RV is when you're operating it on a for-hire basis, either as a driver for hire or as a transporter.
The air brakes don't matter, insofar as whether or not a CDL is required. As for the GVW being over 26,000 lbs., yes, unless your vehicle falls in criteria for the farm vehicle, military vehicle, emergency vehicle, or recreational vehicle exemptions.
If it's not a firefighting or first response vehicle, recreational vehicle, registered farm vehicle, or military vehicle (operated by military personnel in the course of their duties), then yes - not because of the the air brakes, but because of the weight rating of more than 26,000 lbs. GVWR.
Only if it's either hauling a quantity of hazardous materials which requires placarding, or if it's a bus designed to transport more than 15 persons (including the driver).
Air brakes have absolutely ZERO determination in whether or not a vehicle requires a CDL.
You only need a CDL for a vehicle under 26,000 lbs. GVWR if it's designed to carry more than 15 passengers (including the driver) or if it's carrying hazardous materials in an amount which requires placards to be displayed.
Air brakes have zero determination as to whether or not a vehicle requires a CDL. The only time you need a CDL for a vehicle under 26k is when it's a bus designed to transport more than 15 persons (including the driver) or a vehicle hauling a quantity of hazardous materials which requires the display of placards.
No. Air brakes are not a parameter in determining whether or not a vehicle needs a CDL.
No.
You would have to change the brake pads in your vehicle every 15,000 miles or sooner. It depends on how much you drive your vehicle. The more your drive, the earlier you have to replace the brakes.