This maintenance kit is for 2.5” stacked cylinders manufactured between May 2011 and 2013. These have screw-in style piston check valves that are no longer produced. Therefore, these items are not included in the maintenance kit. If the screw-in style check valve needs replaced, then a current version of the piston assembly would have to be purchased. This cylinder also uses a separate foot valve which is included with the maintenance kit.
With this maintenance kit you will be able to replace most wear items and some hardware to keep your Bison Pump Cylinder running strong!
Bison Pumps offers an upgrade kit that would convert most cylinders to the latest model. For more details visit Cylinder Upgrade Kits.