Break release when truck is not running?

[citizensoldier]

How do you get the air brakes to release on a M51A2 dump truck if the engine is not running to prime the system? My friend is trying to move one for me and niether of us know how to do this? I am a M37 guy mostly and this is my first real BIG truck..
Thank you in advance...

 

[Dieselsmoke]

They aren't air brakes. They are air over hydraulic so no spring brake.

 

[citizensoldier]

What does this mean?

I know they are air over hydrolic.. But doesnt the compressor have to pump up to get the system to work or let go?

 

[Hotshot]

RE: What does this mean?

No.With no air they are just hard to stop.The air is just to make it easeir to engage the brakes.I once had the belt on the compressor break and it was a bear to stop but if you push hard enough you can stop it