Troubleshooting
12 311688L
Troubleshooting
NOTE: Relieve the pressure (page 10) before checking
or servicing the equipment.
NOTE: Relieve the pressure (page 10) before checking
or servicing the equipment.
Problem Cause Solution
Pump cycles at stall or fails to hold
pressure at stall.
Worn check valve balls (26), seats
(31), or ball guides (32).
Replace. See page 20.
Pump will not cycle, or cycles once
and stops.
Stuck or dirty air valve. Disassemble and clean air valve.
See page 16. Use filtered air.
Check valve ball (26) severely worn
and wedged in seat (31).
Replace ball and seat. See page 20.
Check valve ball (26) wedged in seat
(31) due to overpressurization.
Replace. See page 20. Do not
exceed the maximum fluid working
pressure, see page 24.
Clogged fluid dispensing valve. Relieve pressure and clear valve.
Pinched hose line. Check lines.
Pump operates erratically. Clogged suction line. Inspect; clear.
Sticky or leaking check valves. Clean or replace balls (26) and seats
(31). See page 20.
Ruptured diaphragm (9). Replace. See page 13.
Restricted exhaust. Remove restriction.
Air bubbles in fluid. Loose suction line. Tighten.
Ruptured diaphragm (9). Replace. See page 13.
Pump running irregularly. Stroke fre-
quency dropping, coming to stand-
still.
Worn parts. Replace worn parts. Check com-
pressed air supply.
Icing caused by: compressed air too
moist, stroke frequency too high,
local temperature too low.
Remove ice by changing operating
conditions.
Air escapes continually. Damaged air valve cup (15) or seat. Replace damaged parts. See page
16.
Foreign matter inside pump. Check air filter.
Pump does not start, or pressure
fluctuates.
Worn check valve seats. Replace. See page 20.
Inlet strainer blocked, maximum suc-
tion exceeded, hose or seal defec-
tive.
Clean strainer. Replace defective
parts.
Contaminated fluid. Pump installed or
operated incorrectly.
Check fluid supply. Follow installation
and operation instructions in this
manual.
