Checking double check valve operation for spring brakes

[@RC-Heli835]

Do you have single checks on the front of each tank? Both tanks are draining in my dump truck by draining only one tank. They also air up at the same time which they have never done. That just started recently and I'm trying to get it sorted out. Thanks for sharing!

[@Ray哥]

I just want to know where is the “ double check valve” ?

[@Brandonbuilt]

It’s built into the park brake valve itself. He didn’t mention that.