859.0089
7
Pump operates erratically.
Clogged suction line.
Inspect; clear.
Sticky or leaking check valve balls.
Clean or replace. See page 11.
Diaphragm (and backup) ruptured.
Replace. See page 12.
Restricted exhaust.
Remove restriction.
Pilot valves damaged or worn.
Replace pilot valves. See page 12.
Air valve damaged.
Replace air valve. See page 8.
Air valve gasket damaged.
Replace air valve gasket. See
page 8.
Air supply erratic.
Repair air supply.
Exhaust muffler icing.
Use drier air supply or use low ice
muffler (Verder part 819.7000).
Air bubbles in fluid.
Suction line is loose.
Tighten.
Diaphragm (and backup) ruptured.
Replace. See page 12.
Loose manifolds, damaged seats or
manifold o-rings.
Tighten manifold bolts or replace
seats or o-rings. See page 11.
Diaphragm shaft bolt o-ring dam-
aged.
Replace o-ring.
Pump cavitation.
Reduce pump speed or suction lift.
Loose diaphragm shaft bolt.
Tighten.
Exhaust air contains fluid being
pumped.
Diaphragm (and backup) ruptured.
Replace. See page 12.
Loose diaphragm shaft bolt.
Tighten or replace. See page 12.
Diaphragm shaft bolt o-ring dam-
aged.
Replace o-ring. See page 12.
Moisture in exhaust air.
High inlet air humidity.
Use drier air supply.
Pump exhausts excessive air at stall. Worn air valve cup or plate.
Replace cup and plate. See page 9.
Damaged air valve gasket.
Replace gasket. See page 8.
Damaged pilot valve.
Replace pilot valves. See page 12.
Worn shaft seals or bearings.
Replace shaft seals or bearings. See
page 12.
Pump leaks air externally.
Air valve or fluid cover screws loose. Tighten.
Diaphragm damaged.
Replace diaphragm. See page 12.
Air valve gasket damaged.
Replace gasket. See page 8.
Pump leaks fluid externally from
joints.
Loose manifold screws or fluid cover
screws.
Tighten manifold screws or fluid
cover screws. See page 15.
Manifold o-rings worn out.
Replace o-rings. See page 11.
Pump leaks fluid externally through
manifold or fluid cover.
Excessive pump speed or inlet
starvation.
Replace manifold and reduce pump
speed or improve pump feed.
Problem
Cause
Solution