Isx 400st engine brake problem

[Mnahal]

Hi
I own a 2008 volvo vnl 670 with the cummins isx 400st. (I believe it is a cm871 engine) From the day I bought this truck the engine brakes were not functional. I get absolutely no engine braking at positions 1 2 or 3 engine brake settings. I have had several mechanics including volvo dealership look at it with no success. I have replaced and check engine brake on off switch, low high switch, engine brake harness, both silanoids, and performed OVERHEAD twice. No success.

I few days ago I thought I take a look at this myself. I pulled the engine cover and ran the motor. Using a screwdriver I manually activated each silanoid rockers didnt activate. The only change I saw was that there was engine oil coming out the bottom of each silanoid when activated.

Another thing I tried was to activate silaniod manually and tap the rocker by hand and only then the rocker would activate. What's the problem low oil pressure? Internal oil leak? Bad rockers? Please help

I also made a short YouTube video of what I tried with the link below please view?

Watch "Cummins isx cm871 engine brake not working" on YouTube
https://youtu.be/y58ttsoC-qg


Is it normal of engine oil to drain from bottom of silaniod when activated?

Thank you

[Signature620]

Could have clogged rocker shafts limitting the flow of oil. Very strange for new solenoids to pass oil like that.