Graco LD Series, Instructions Manual

Page: 23 / 32

Troubleshooting
3A1334P 23
Troubleshooting
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.
Oil Models
Problem Cause Solution
Pump runs but no fluid output
Pump is not fully primed
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.
Oil leakage Check connection and tighten.
The piston valve is not seating prop-
erly or the piston o-ring is damaged
Check and replace parts as needed.
Exhausted fluid supply Refill and reprime.
The pump inlet filter is blocked Clear the filter
The suction tube (hose) has an air
leak Check the connection and tighten as
needed.
Pump fails to operate or stops
Damaged pilot valve
Service pilot valve.
Lower air pressure to prevent reoc-
currence.
Damaged main air valve
Replace air valve.
Lower air pressure to prevent reoc-
cur an ce.
Inadequate air supply pressure or
restricted air lines.
Increase air supply; clear.
Closed or clogged dispensing valve
Open valve if closed. Clear clog if
necessary.
Clogged fluid lines, hose valves, etc. Clear clogs.
Damaged air motor Service air motor.
Erratic or accelerated operation
Exhausted fluid supply Refill and reprime.
Damaged valve gasket
Replace valve gasket.
Lower air pressure to prevent reoc-
currence.