Joined: Aug 2010
Posts: 12,750
Likes: 2,111
From: Madison, WI
Bikes: 1961 Ideor, 1966 Perfekt 3 Speed AB Hub, 1994 Bridgestone MB-6, 2006 Airnimal Joey, 2009 Thorn Sherpa, 2013 Thorn Nomad MkII, 2015 VO Pass Hunter, 2017 Lynskey Backroad, 2017 Raleigh Gran Prix, 1980s Bianchi Mixte on a trainer. Others are now gone.
I also have a Lezyne pump that threads on instead of clamping onto the Presta valve. My first time using that, when removing the pump the valve core stayed on the pump which emptied the tube. I just tightened the valve cores with an adjustable wrench, have had no problems since. I would not recommend using loctite where it could contaminate a valve seat, I only use loctite on nuts and bolts.