Combines header raise leak down etc

[Jeremy]

I don't have a parts book handy, but assuming this is in the valve stack, is it a fitting inside the body that takes a special socket of some sortIJ

 

[tbran]

unfortunatly the seat is on the inside next to combine. A small allen wrench will wedge in and can be used to pull out the seat. Just a little patience and wigglin' in the right place works wonders!