Cm570 engine brake vibration and weak jakes

[Marat]

So I did the injector leak test. Cylinder #1 failed.
Going to replace that one. However That cylinder still doesnt fire at all when jakes are engaged. Wether its from inside the cab or doing it manually, the rocker moves around but not like the other ones. I tested the solenoids all 3 are within soec at 8-9 ohms. All 3 click the same when given 12v. I even swapped out the solenoids to no change. Took out the plunger/pistons from that rocker and a good working one. Engaged jakes to compare oil flow, its as good as the other ones. Im pretty much at a dead end now. Probably gonna have to pull the rocker shaft off and inspect further. Definitely gonna change that one injector as well