Originally Posted by MNtraveler
Next dumb question! We were surprised on our new 2401R to find that the extension tubes for both inside rear tires seem to have "nothing" inside the tubes. When putting a pressure gauge on the tubes, no reading can be taken and there is no apparent way to add air. What's this about? Shouldn't the extender tube extend the ability to check and add air?
There are two types of hose extenders
"Airless" These have a long wire inside that is suppose to open the valve core in the valve on the tire. This would then fill the hose with the air from the tire and allow a pressure check to be made or for air to be added to the tire. You can confirm this with the hose removed and press the pin in the outboard end. Is there a pin that moves at the tire end? If so you have an Airless hose extender. If you can't measure or add air with this host then the valve core in the valve stem on the wheel is set too far into the valve body. You may need a new core. I believe that with this type hose you should not hear air leak when you first attach the hose.
Pressurized hoses have a regular valve core at the outer end and a solid pin at the tire end. When you screw this type of hose on you should hear air leak out till the hose is tightened 1/4 to 1/2 turn past the point when air leak stops. This means the hose is carrying the air from inside the tire all the time. So when you check the pressure or add air you only open the standard valve core at the outer end.
Hope this helps.
I write a blog on RV tire application and safety. RVTireSafety.com
Also give seminars on tires at RV events across the US. 40 years experience as tire design & quality engineer for major tire mfg. Freelander 23QB on Chevy chassis is my RV