Mastic Handgun
5
Part 1040769A
E
2004 Nordson Corporation
Repair
Repair consists of replacing the valve stem and seal.
NOTE:
Lubrication requirements and torque
specifications for the parts are listed on
Figure 4.
Remove the Valve Stem and Seal
See Figure 4.
1. Relieve system and material pressures.
! CAUTION !
To prevent loosening the fluid tube, use a
wrench on the fluid tube hex when removing
the material hose.
2. Trigger the gun to purge residual material. Using a
wrench on the fluid tube hex, disconnect the material
hose from the gun.
3. Remove the valve stem (4) and seal (11):
a. Remove the spring retainer screw (5) securing the
spring (6).
b. Using a 3 mm hex key, remove the spring
housing (7).
c. Remove the valve seat (3) from the gun body (13).
Check the washer (14) for any damage and
replace if necessary.
d. Remove the bracket (8) and nut (9) from the
valve stem.
4. Remove the valve stem from the gun body. Inspect
the valve stem for wear or damage and replace if
necessary.
5. Remove the seal retainer (10) from the gun body and
replace the seal.
Install the Valve Stem and Seal
1. Lubricate the new seal (11) and install it into the gun
body (13) with the seal lips facing toward the gun
body.
2. Lubricate the threads of the seal retainer (10) and
install it into the gun body. Tighten the seal retainer.
! CAUTION !
Do not push the valve stem through the seal.
Turn the valve stem clockwise when
installing it to prevent damage to the seal.
3. Install the valve stem (4):
a. Lubricate the valve stem and carefully install it into
the gun body and through the seal. Thread the
nut (9) onto the valve stem.
b. Install the bracket (8) and spring housing (7) onto
the valve stem.
c. Lubricate the threads of the valve seat (3) and the
and the washer (14). Install the washer and valve
seat onto the gun body and tighten.
d. Lubricate the spring (6) and install it into the spring
housing.
e. Lubricate the threads of the spring retainer
screw (5). Install the spring retainer onto the gun
body and tighten securely.
4. Insert an
1
/
8
-in. hex wrench into the hole in the spring
retainer screw and into the spring housing. Turn the
spring housing and stem nut to change the trigger
travel and the size of the valve opening. Tighten the
stem nut securely.
5. Using a screwdriver, turn the spring retainer screw as
needed to close the valve stem.
6. Using a wrench on the fluid tube hex, connect the
material hose to the gun.
