Joined: Feb 2006
Posts: 571
Likes: 0
From: Canberra, Australia
Bikes: Salsa mtb * 3, Intense mtb * 1, Abeni SS rd * 1, Salsa road/touring * 2, Trek Damn one * 1, Vintage/projects * many
Symptom fits with damaged master piston seal. Holds pressure briefly then loses it as fluid flows back past the piston into the reservoir. Try swapping the lines to confirm.
- joel