Echo MS-40BP manual Collar, Disassembling and Repairing the Piston Pump

DISASSEMBLING AND REPAIRING THE PISTON PUMP

C

B

A

Figure 1

1)Remove the cotter pin and pump handle. With the pump facing towards you, lay the unit on its back (Figure 1). Loosen the hose clamp and remove the sprayer hose. Caution: There could be residual liquid in the hose and pressure cylinder. Remove the nut and bolt from the protective cap and remove the cap (ref: figure 9). Rotate the pump shaft in order to reach two lever bolts (A). Using an allen wrench, remove the lever bolts. Pull the piston assembly (B) out of the piston cylinder(C).

2)Remove the piston cylinder assembly by turning the piston cylinder

counter-clockwise when viewing the sprayer from the bottom. Caution: The piston cylinder may have sharp edges.

Figure 2

3)Check for vertical scratches on the inside of the piston cylinder and the piston. If one or both are scratched, replace them.

Figure 3

Collar

4)To replace the collar, push it off of the crown of the piston with your thumb. You will see form fitted slots to install the new collar on to the piston crown.

Figure 4

Piston

Cylinder

Intake
Upper
Valve
plate
Lower	Outlet
Valve plate	Passage

Figure 5

Pressure cylinder base rib

Piston cylinder tab

Figure 6

5)There are 2 valve plates on the piston cylinder, one on the inside of the cylinder and one on the outside top. The valve plates are held in place with a screw and washer and can be removed and replaced using a Phillipshead screw driver. The 2 o-rings can be removed and replaced as well. Insure that the o-rings are positioned in the o-ring grooves in the piston cylinder.

6)Grease the 2 O-rings on the piston cylinder (do not get any grease on the valve plate) and screw the piston assembly into the pressure cylinder base. Screw the piston cylinder clockwise until tight and the bottom O-ring is no longer visible. When properly placed, the tab on the piston cylinder will line up with the rib on the pressure cylinder base.

7E