Exhaust pressure governor fail with pictures

Need some help before investing $900 for a new EPG. Attached are some pictures of the EPG shutter on a Volvo D12 engine. Just want to know if that shutter is stuck partially closed, and does not retract all the way back when there is no pressure form the AVU. To me it looks like it is not fully open and thus restricts exhaust gasses form escaping freely. Otherwise I can tell that it is working (can hear it whirling), warm-hold function, idle-EGR function, just the exhaust brake function is definitely mediocre.
Anyway, has anyone seen a NEW or GOOD EPG and tell me if if the shutter is so close the opening when the truck is shut down.

 

Any thoughts?

 

What do you mean by disable? Just to put a plug to the Epg airline, or unplug the Air valve unit on the cool engine side?

 

Exactly D12D

 

Correct me if I am wrong but Volvo Engine Brake works in conjunction with Exhaust brake, thats why if you unplug AVU you will lose VEB. In other words you need EPG for for your engine brake to work even if you fool the ECM to think that your EPG is working fine.