Graymills DDP 1' Aluminum Pump - Manual (Page 13)

13
Troubleshooting
WARNING
To reduce the risk of serious injury whenever you are
instructed to relieve pressure, always follow the Pres-
sure Relief Procedure on page 11.
D Relieve the pressure before checking or servicing the
equipment.
D Check all possible problems and causes before disas-
sembling the pump.
PROBLEM CAUSE SOLUTION
Pump cycles at stall or fails to hold
pressure at stall. Worn check valve balls (301), seats
(201) or o-rings (202). Replace. See page 17.
Pump will not cycle, or cycles once
and stops. Air valve is stuck or dirty. Disassemble and clean air valve. See
page 15. Use filtered air.
Check valve ball (301) severely worn
and wedged in seat (201) or manifold
(102 or 103). Replace ball and seat. See page 17.
Check valve ball (301) is wedged into
seat (201), due to overpressurization. Install Pressure Relief Valve.
Dispensing valve clogged. Relieve pressure and clear valve.
Pump operates erratically. Clogged suction line. Inspect; clear.
Sticky or leaking balls (301). Clean or replace. See page 17.
Diaphragm ruptured. Replace. See pages 18–20.
Restricted exhaust. Remove restriction.
Air bubbles in fluid. Suction line is loose. Tighten.
Diaphragm ruptured. Replace. See pages 18–20.
Loose inlet manifold (102), damaged
seal between manifold and seat (201),
damaged o-rings (202). Tighten manifold bolts (106) or re-
place seats (201) or o-rings (202). See
page 17.
Loose diaphragm shaft bolt (107). Tighten or replace (pages 18–20).
Damaged o-ring (108). Replace. See pages 18–20.