172-65254MA-04 (A-COS-10) 22 Apr 2020
15
Disassembling the Pilot Section
The diaphragm is removed by utilizing the notch in the pilot body. Loosen the pilot
valve seat with a box wrench and remove it. Lift the pilot valve spring up and out with
a pair of tweezers. Then loosen and remove the screen holder to remove the screen.
Check for any fault on the pilot valve seat, the seat of the pilot valve, flaws on the
gaskets, and clogging of the screen. Check for deformation, corrosion or faults on
the diaphragm. The diaphragm should be convex (open downward), with the printed
UP mark on the top.
Diaphragm
Pilot Valve Seat
& Gasket
Pilot Valve
Pilot Valve Spring
Gasket
Pilot Body
Notch
Pilot Screen
Pilot Screen Holder
& Gasket
Plug
Hex Bolt
Disassembling the Piston Section
Remove the pilot body after loosening and removing the hex bolts (stud bolts).
During this process, pay attention not to lose the connecting tubes (2).
Remove the piston and the cylinder from the body. Then remove the piston rings and
the tension rings from the piston. Do not apply too much force when removing the
piston rings and tension rings.
Check for the interior of the cylinder, the exterior of the piston rings, the small hole
on the piston and the cylinder gasket for any fault or abnormality.
Piston Ring
Tension Ring
Piston Ring
Tension Ring
Piston
Cylinder
Cylinder Gasket
Gasket
Connecting Tube
Connecting Tube
