Graco 239877, Instructions Manual

Page: 11 / 16

Troubleshooting
308883S 11
Troubleshooting
1. Follow Pressure Relief Procedure , page 5, before
checking or repairing gun.
2. Check all possible problems and causes before dis-
assembling gun.
Problem Cause Solution
Pump fails to operate
Inadequate air supply pressure or
restricted air lines Increase air supply and/or clear
restriction
Closed or clogged valves Open and/or clear
Clogged fluid lines, hoses, valves,
etc.
Relieve pressure. Clear obstruction
Damaged air motor
Assess damage and service air
motor
Exhausted fluid supply Refill and reprime or flush
Continuous air exhaust
Worn or damaged air motor gasket
or seal Asses wear or damage and service
air motor
Erratic pump operation
Exhausted fluid supply Refill and reprime or flush
Worn pump seals Replace
Damaged shovel tube Replace
Damaged check seat
replace pump piston or shovel rod
(or other damaged part)
Pump operates, but output low on
upstroke
Worn piston seal Replace
Damaged upper check seat Replace pump piston
Pump operates, but output low on
downstroke
Worn fluid intake seal Replace
Damaged lower check seat Replace shovel rod
Pump operates, but output low on
both strokes
Inadequate air supply or restricted
air line Increase air supply and /or clear
restriction
Closed or clogged valves Open and/or clear
Exhausted fluid supply Refill fluid supply and reprime pump
Clogged fluid lines, hoses, valves,
etc.
Relieve pressure. Clear obstruction
Worn seals Replace
Grease leaking from muffler plates Worn throat seal Replace