Elec boost pump repair

[Gmovies]

Anyone here ever try to split one of these open? This is Airborne electric boost pump 1B5-6 (same as other manufacturer 1B5-6). The long stud coming out of the cap was bent so I removed the pump from the aircraft and straightened it. This stud is for "+" terminal for electrical wire attachment. I noticed that the stud was just a bit lose and can be easily turned with a small wrench. I'd like to remove the end cap and inspect any wiring attached to the terminal inside the cap. The two large bolts come off easily but the cap itself doesn't want to come off. It moves just a bit but it feels like there may be brushes attached to the rotor or perhaps an O-ring. I did a google search but couldn't find any repair or parts manual. No videos on YouTube either. Rebuilt pump costs $900 with core exchange so I'd like to repair it myself for experimental use. Appreciate any advice on this.

Thanks,
Paul Klusman