Wheel Simulator Hses

Valve extenders attached to the wheel simulators is asking for trouble as you have found out. You can use this as a learning moment and do something different before something worse happens. If you lose one, it takes the valve stem and you don't notice it you are likely to have a tire come apart. A disintegrating tire can do a lot of damage to an RV.

Let's make sure we use the right terminology, "extensions" are cheap accessory things that screw onto the existing rubber valve stems so that you can check pressure and add air with "beauty discs" in place. They tend to unscrew and leak and can cause rubber valve stems to crack and leak from vibration causing tire failure from under-inflation and collateral damage to underside parts of RV. Having long custom formed SOLID brass or steel valve stems installed, using Borg or Tireman, or custom made ones from a truck tire store, is the safe and reliable approach costing up to $200 parts and labor. Checking air will be easy with no need for gymnastics and cussing as you release air instead of adding it.

no law sayin' trucks need hubcaps

who needs those shiney tin disks, anyhow?

RVs might be more fun to look at if we spray paint the rims

why let that 'rock my RV' guy have all the fun?

After the squeaking clicking and creaking of the wheel simulators drove me nuts they got retired. If you want to keep them from jettisoning you can buy stainless steel ties (like the nylon ones) that can help keep them from shedding. Look on Amazon.

...and do not use hose type extensions. They suck. Been there leaked that. Get rigid ones if you are going to use any extensions (Tireman, etc). You can also use Alligator V2B air through caps which makes life easier for those not using Tireman stuff.

I took mine off and am just running the bare white wheels. I check my air pressure before every trip and quickly had grown tired of removing them each time. I figured it was only a matter of time before a pot hole sent a few of them flying anyway.Now checking the air is a breeze.

Replacing the air line is the least of it. If the departing wheel cover/simulator doesn't tear up enough of the air line and valve to deflate a tire or two, it'll flail around and damage the coachwork. Along the lines of a blowout and flailing tire tread.
Friends should't let friends use Extenders. NO extenders and suffer, OR Tire-Man.

With the Tire Man valve stems you won't have any of those troubles.

No leakage or flailing around like the hoses.

use tire man valve stems.

Air line Kit? Do you mean Valve Extenders?

If so, mine are attached to the wheel, not the cover.