Specifications

PAGE 28 — MAYCO C30HDZ PUMP — OPERATION AND PARTS MANUAL — REV. #12 (04/03/12)
Figure 12 shows the relationship between the return spring, the compensator spring and the rocker arm to maintain a smooth
performance. DO NOT tighten the bolt (Item 1) completely, the rod end must be able to move.
The return spring is installed to eliminate shock and stress between the cam roller and the cam weldment when the pump is in
operation. If the
return spring is removed or replaced for any reason, maintain the backing plate dimension (3-inches) as shown to
produce proper pre-loading of the spring for a smooth performance.
The pumping piston (Figure 11) is forcing the material past ball (B) and out to the nozzle, also seating ball A so that the material will
not flow back to the hopper. This action also fills the compensating piston for the next stroke.
Figure 11. Pumping Pistons
Figure 12. Return Spring, Compensator Spring and
Rocker Arm Interaction
HOW IT WORKS