
25
PI-120
March 2020
7. Connect supply hose to back of seal adapter and re-install hose sup-
port burst shield. Do not operate without hose support burst shield.
8. The gun should now be ready to use. Increase pressure slowly until
desired blast pressure is reached.
6.2 REPLACING THE DRIVE BELT
If barrel stops rotating, or rotates erratically, the drive belt may be dam-
aged. Inspect and replace belt as follows:
1. Remove signal hose from secondary control handle by pushing in on
ring while pulling hose.
2. Remove nozzle head.
3. Using a 3/16” allen wrench, remove the two housing retainer screws
(15) and slide barrel extension/housing assembly off of front barrel.
Inspect drive belt for damage.
4. If damaged, replace belt (22) by removing driver timing pulley (3). Us-
ing a 1” spanner wrench (PN 63789) and 3/16” hex wrench, remove
the driver pulley from the air drill shaft.
5. Remove driver pulley and belt and install new belt over barrel and
driver pulley.
6. Replace driver pulley onto air drill.
7. Increase pressure slowly until desired blast pressure is reached.
Front barrel should rotate at approximately 2000-2500 RPM at 90 psi
supply air pressure (1500-2000 RPM for 48” gun).
6.3 REPLACING THE MAIN BEARING
If barrel stops rotating, or rotates erratically, the main bearing may also
be damaged. Inspect and replace bearings as follow:
1. Complete steps 1 - 5 of previous section 6.2.
2. Remove front barrel.
3. Using a small pick or screwdriver, remove the spiral retainer ring (4m)
from the swivel shaft.
4. Slide driven pulley (4k) and key (4e) from shaft.
5. Using a 5/32” allen wrench, remove the six swivel body capscrews
(4f).
6. Separate the body from mounting plate (4h).