Question my brake pedal

Hi there,
I am curious that my brake pedal can not up and down after the engine turn off. Is this normal? I think it should up and down I mean that I can brake even engine turn off huh?
Thanks

 

I think I've pieced this together...

Is the pedal immediately stiff and won't go down at all after turning the truck off? Or does it go down a few times before getting stiff? The latter is normal. When you repeatedly press on the brake after turning off the truck, you're creating pressure in the hydraulic system which will build up and eventually stop your pedal from going down. This can put pressure on your brake lines and fittings as well, so it's not recommended that you do this.

 

Yes. It go down few time before getting stiff... And the pedal can not move any more. Is this normal? Well, I currious that what the car die at a middle traffic, we can not use brake huh!
Thanks

 

Yes, that is normal. Nothing to worry about

 

Thanks Blue!

 

Truck needs to be running for the brake booster to work.

This is the same for any vehicle, your power steering won't work so good either if truck shuts off.
You'll still have brakes and power steering, but all the work is up to you. No help from he truck once it shuts off.