I was watching a TV program the other night called Ice Road Truckers and saw trucks being towed without the air pressure being built up and the same with trailers. In the little corner of the world where I live that would be imposible cause without air pressure the brakes are locked on. Can someone please explain ( ozzies will get this). I'm just curious and it's no big deal
The chambers normally have a bolt that can be used to cage the brakes. If the bolt is missing you can, in a pinch, back the slack adjusters way off.
Iv'e also seen another show of trucks being draged out of snow on the Cocohola Pass(spelling), Jamie Davis and his crew. Some of these trucks were in over a metre of snow and I didn't see any sign in the video footage where someone had dug under the rig to release the breaks yet the wheels where free turning. I understand that theyr'e TV show with a licence to ********, but
We would always just unscrew the wet tank drain valve and screw in an air chuck, then use air from the tow truck to release the brakes. It is pretty easy when the air tanks are located under the driver step.
Gotta remember all those trucks were running when they went in, so they may well have had air up enough to release the parking brakes. Sometimes they just don't bother to show the process but you can see the air line from the tow unit. Sometimes they just get lucky and the wheels will turn enough (out of adjustment) so that they can drag the truck/trailer to a pullout to open the highway up, then do what they need to do to make it towable to the yard. They do carry a box of caging bolts in every wrecker, lol.