Savana 3500 Oil Sending Unit problem??

[KB1]

I have a 2005 GMC Savana 3500 V8 6.0L. The oil gauge goes straight to maximum and stays there. It also does this even if i only turn the key to the on position without starting the van. I didn't notice any problems the day before this started so I am assuming that it is a faulty seeding unit. I was just wondering if anyone agrees with this assumption, is there a way to manually check the pressure, where is the sending unit located and does anyone know where i can find instructions on how to replace it. The only repair manuals i have been able to find are online and require 4 to 6 weeks for delivery. I have also read that this can also be caused by a defective oil filter. I did see a small dent in the oil filter when i checked it.
Thanks for any help.

 

[Boattail]

I know this is an old thread but I just joined today and hope this helps someone. KB1 is right because mine was doing the same thing and replacing the sending unit fixed it. Here is a link to a video from 1A auto (no affiliation). The job is a bit of a PITA.