air brakes release with engine not running

[Karl kostman]

Hey guys I am sure this is a stupid question but the only answer I could find in the TMs was to cage the brakes, I am looking for an easier way. I am taking delivery of an M920 and since its so cold here there is a possibility of the engine not starting, and if that is the case that means NO air pressure to release the brakes! My question is can I introduce air pressure into the system through one of the glad hands to pressurize the air system and release the brakes?
Thanks for you input on this, its a new truck to me and I am trying to cover all possibilities!
Karl

 

[dilligaf13]

Yes. People have been known to place an air compressor in the bed and run air hoses to the glad hand, to move the trucks in a pinch. Just charging the system, off the glad hand, will get you about 5 (plus or minus) applications off the brakes.

 

[Trailboss]

Stating the obvious here, but in the interest of safety since you won't be in the cab when you attach the air hose, make sure the parking brake is set before you add air, as the truck may roll when the spring brakes release.

 

[dmetalmiki]

Apart from applying the handbrake CHOCK the wheels each way. (then(you can)) CHARGE the air tanks to release the brakes through the EMERGEANCY <RED> glad hands.

 

[Coffey1]

And watch it if the truck bleeds air down in a hour or two and don't have a constant air supply to it they will lock again.
Would not be fun at speed.

 

[fasttruck]

I assume everyone is talking about the glad hands behind the front bumper not the ones on the back of the truck. I don't know about a 920 but many civi airbraked vehicles have check valves that prevent feeding air from other in front of the air tank.

 

[Coffey1]

I believe that would be correct.

 

[Suprman]

The red should feed air into the tanks front or back. There are no check valves on the red front or back if the line comes off before you close the valve behind the gladhand the air will escape.

 

[jw4x4]

Something else to consider- just because the air system is fully charged does not guarantee that the brakes will release. Sometimes if they haven't been used in awhile, you may have to introduce some percussive maintenance into the equation.

 

[74M35A2]

Bring starting fluid. That engine will fire.

 

[tbar123]

I know the main question was in regards to a truck that won't start, but if you do get it started and the brakes are still locked.In my experience with frozen brakes due to the cold, rocking it will usually unlock the brakes.Forward reverse.If not, pump the brakes a few times,sometimes ice in the air lines melts just enough to free the brakes. It's worked a few times for me with frozen trailers.

 

[Karl kostman]

Thanks for your help guys the truck is supposed to arrive at my location around 11:00 tomorrow morning, and its supposed to get down to 3 degrees tonight, I dont like to use ether but in this case I have pretty limited options. I will be using my 925A1 to supply air to the truck and we shall see what happens. Pics will be shortly pending!
Karl

 

[rosco]

I have an "air-up" chuck on my tractor. I add air from the shop compressor to pre-fill the tanks, so that I don't have to run a stinky diesel in the shop so long, before I can back it out. It depends on the truck's system, as to where you put it, but it needs to be handy to get to.

 

[R Racing]

Do you have a slave cable? You could use it off of your m925. If it won't turn over than I'd bet you have a shorted battery ( I had 2 that kicked my but. 3 trucks with both slave and jumper cables couldn't get it to turn over ) pull the batteries out if that happens then jump it.

 

[R Racing]

Also the m920 has a either start system built into it. So Don't be afraid to use it.

 

[Bighurt]

Also the m920 has a either start system built into it. So Don't be afraid to use it.

I agree, slave and ether are the only thing that bring the NTC-400 to life when temps are that low for my M915a1. Just follow the instructions.