So I just bought this m813a1 about two months ago, so I don’t really know the history. It’s had a bad air leak since I bought it. So I found my poppet valve was leaking at the open port after many hours and days of searching for leaks.Couldn’t find a rebuild kit online. So I took off cleaned, put new orings on, and made new gaskets. Installed it and same crap. Took lines off from transfer case air cylinder to eliminate that to find leak. So I noticed it was only leaking from the one poppet closest to the seat. Messing around I found when shifter is just barely put in reverse it stops leaking. So I got the idea of backing the 4 mounting bolts off from the poppet. Leak stopped. So my question is should a guy put more shims in between poppet and trans (there is one set along with o rings)or is something else going on? Anyone else come across this before?