Engine not workign good when parking brakes are on VOLVO 780 D13

Hello,

I noticed that when on parking with brakes on my truck is not working as good as when with brakes off. With parking brakes on the RPMS are shaking little bid and the engine is working much harder and louder. As soon as I turn off the parking brakes all is good and back to normal. There are no codes on the engine

Did you anyone had a similar issue or maybe any idea what could be the cause?

Volvo vnl 780 D13 with Ishift

 

Same thing, RPMS shaking little bid and engine is working harder. The only thing that is changing it that I found is the parking brake when it's on the whole thing happens, when off engine works great.

 

When on parking with brakes turned on there is the issue, when on parking with no breaks turned on there is no issue, when driving all is good, no codes at all

 

Yes I did