Hitachi 308640 - Manual (Page 14)

14 308640
Troubleshooting
WARNING
INJECTION HAZARD
To reduce the risk of a fluid injection
injury, follow the Pressure Relief Proce-
dure on page 7 before checking or
servicing any of the system equipment and when-
ever you are instructed to relieve pressure.
NOTE:
D
Check all possible remedies in the troubleshooting
charts before disassembling the gun.
D Some improper patterns are caused by the
improper balance between air and fluid.
General Troubleshooting
Problem Cause Solution
Fluid leakage from back of fluid
needle Worn packings or needle shaft Replace external needle packings or
entire fluid needle cartridge. See
page 16.
Air leakage from front of gun Air valve not seating properly Clean/service air valve. See page 16.
Fluid leakage from front of gun Fluid needle worn or damaged Replace fluid needle cartridge. See
page 16.
Worn diffuser-seat housing Replace the diffuser-seat and gasket.
The gasket must be replaced when-
ever the diffuser-seat is removed.
See page 16.
Fluid in air passages Fluid tip seal leaking Tighten or replace fluid tip. g
Leaking around diffuser-seat housing Replace the diffuser-seat gasket. The
gasket must be replaced whenever
the diffuser-seat is removed. See
page 16.
Fluid inlet fitting leaking Replace the fluid fitting gasket. The
gasket must be replaced whenever
the fluid fitting is removed. See
page 17.
Slow fluid shut-off Fluid buildup on fluid needle cartridge
components.
Diffuser-seat is overtightened.
Remove and clean or replace the
fluid needle cartridge. See page 16.
Remove diffuser-seat and replace
diffuser-seat gasket. Torque diffuser-
seat to 90–100 in-lb (10.2–11.2
N
S
m).