Komatsu 830E-AC Shop Manual page 952

A/C DRIVE BELT CHECKOUT PROCEDURE
This procedure must be performed each time any
component in the accessory drive is serviced, such
as replacing a belt or removing the compressor. In
addition, a 250 hour inspection of the AC drive belt is
mandatory. The belts must be inspected for
indications of wear and damage that may hinder
performance. Replace as necessary and perform the
following procedure.
Pulley Alignment
1. Install alignment tool (EL8868) onto the pulleys
to check the alignment. Refer to Figure 4-15. If
misalignment of the pulleys exceeds 3 mm
(0.13 in.), the position of the compressor must
be adjusted.
Belt Tension Check
NOTE: This procedure has been written for use with
belt tension tool (XA3379), shown in Figure 4-13.
Other tension tools may differ in functionality.
FIGURE 4-13. BELT TENSION TOOL - XA3379
2. Refer to Figure 4-16 for the proper distance
from the centerline of the drive pulley to the
centerline of the compressor pulley. Set the
tension tool accordingly on the "deflection"
scale by moving the deflection O-ring to the
corresponding distance on the scale.
3. Slide the O-ring for the "force" scale to zero.
N4-26
FIGURE 4-14. DEFLECTION MEASUREMENT
4. Find the approximate center of the belt between
the two pulleys. Place the tip of the tool onto the
outer face of the belt and apply pressure, as
shown in Figure 4-14. The tool must be
perpendicular to the belt. Push on the tool until
the bottom edge of the deflection scale O-ring is
even with the outer face of the adjacent drive
belt. If only one belt is used, rest a straight edge
across both pulleys to serve as the indicating
plane.
5. The O-ring on the force scale indicates the
force used to deflect the belt. The belt must
deflect 5.3 mm (0.21 in.) under a force of 1.6 ±
0.1 kg f (3.44 ± 0.11 lbf). If not, adjust the belt
accordingly and recheck the tension.
Operator Comfort 10/06 N04031