8
Vacuum System Operation
and Maintenance Manual
Belt Adjustment
1. Turn off the truck chassis engine and remove the switch key from the ignition.
2. Remove the blower belt guards.
3. Loosen the four 5/8" bolts holding both ends of the turnbuckles.
4. Loosen the two 1" bolts holding the drive bearing weldment to the frame.
5. Loosen the jam nuts on the turnbuckles.
6. Turn the turnbuckles until a force of 20 to 30 pounds applied midway between the sheaves at 1/2" deflection is
acquired.
7. Be sure to turn both turnbuckles an equal distance.
8. Check sheave alignment with a straight edge or string, making sure the straight edge or string contacts the face
of both sheaves immediately above the shafts at the same time, to make sure there is no angular misalignment or
offset between the sheaves.
9. If a small amount of adjustment is necessary this may be accomplished by turning one or the other turnbuckle.
10. If a larger amount of adjustment is required it may be necessary to shim one or the other pillow block bearing.
11. After all adjustments are accomplished, tighten the two turnbuckle jam nuts.
12. Tighten the two 1" bolts holding the drive bearing weldment to the frame.
13. Tighten the four 5/8" bolts holding both ends of the turnbuckles.
14. Reinstall the blower belt guards.
15. Reinstall the switch key in the ignition, start the chassis engine, and engage the blower.
16. Visually check for excessive belt slap and readjust if necessary.
SAFETY NOTE:
NEVER
run the blower without the belt guards in place.
