Troubleshooting - Graco LD Series Instructions Manual

Troubleshooting

Oil Models
Problem
Pump runs but no fluid output
Pump fails to operate or stops
Erratic or accelerated operation
3A1334P
NOTE: Check all other possible problems and solutions
before disassembling the pump. Before you troubleshoot
problems using the table below, relieve the pressure
and disconnect the pump fluid line. If the pump starts
when the air is turned on again, the fluid line, dispensing
valve, etc. clogged.
Cause
Pump is not fully primed
Oil leakage
The piston valve is not seating prop-
erly or the piston o-ring is damaged
Exhausted fluid supply
The pump inlet filter is blocked
The suction tube (hose) has an air
leak
Damaged pilot valve
Damaged main air valve
Inadequate air supply pressure or
restricted air lines.
Closed or clogged dispensing valve
Clogged fluid lines, hose valves, etc. Clear clogs.
Damaged air motor
Exhausted fluid supply
Damaged valve gasket
Troubleshooting
Solution
Crack a fitting at the outlet of the
pump to allow a slow leak to purge
any air in the pump. Repeat start up
procedure, page 10.
Check connection and tighten.
Check and replace parts as needed.
Refill and reprime.
Clear the filter
Check the connection and tighten as
needed.
Service pilot valve.
Lower air pressure to prevent reoc-
currence.
Replace air valve.
Lower air pressure to prevent reoc-
cur an ce.
Increase air supply; clear.
Open valve if closed. Clear clog if
necessary.
Service air motor.
Refill and reprime.
Replace valve gasket.
Lower air pressure to prevent reoc-
currence.
23