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5.5.2.2
Checking tensioner spring tension
A belt tension gauge will not give an accurate
measurement of the belt tension when an automatic
spring tensioner is used. Measure the tensioner spring
tension using a torque wrench, following the
procedure below:
1. Release the tension on the belt by using a long-
handled 1/2” drive tool in the square hole on the
tensioner arm. Remove the belt from the pulleys.
2. While the belt is removed, inspect pulleys and
bearings. Rotate and check for hard turning or any
unusual sounds. If pulleys or bearings need
replacement, contact Atlas Copco.
3. Release tension on the tensioner arm and remove
the drive tool.
4. Put a mark (A) on the swing arm of the tensioner
as shown below:
5. Measure 21 mm (0.83 inch) from (A) and put a
mark (B) on the tensioner mounting base.
6. Install the torque wrench so that it is aligned with
the centres of the pulley and the tensioner.
7. Rotate the swing arm using a torque wrench until
marks (A and B) are aligned.
8. Record the torque wrench measurement and
compare with the following specifications:
Spring tension: torque 18-22N•m (13-16 lb-ft)
9. Replace the tensioner assembly as required.
5.5.2.3
Replacing fan and alternator belts
1. To replace a belt with
automatic
tensioner,
release the tension on the belt using a breaker bar
and socket on the tension arm.
To replace a belt with
manual
tensioner, release
tension at the belt tensioner.
2. Remove the poly-V belt from the pulleys and
discard the belt.
3. While the belt is removed, inspect pulleys and
bearings. Rotate and check for hard turning or any
unusual sounds. If pulleys or bearings need
replacement, contact Atlas Copco.
4. Install a new belt, making sure the belt is correctly
seated in all pulley grooves. Refer to the belt
routing below:
A
Threads on the belt tensioner roller
cap screw are left-hand threads.
C
A
B
!
A
T
CP
CSP
FD
I
