Bearing Inspection; Automatic Belt Tensioner Bushing Wear; Belts And Idlers Visual Inspection; Engine Protection Strategy - PREVOST H3-41 Maintenance Manual

SECTION 01 : ENGINE

4.1 BEARING INSPECTION

1. First, set parking brake, turn the ignition
OFF and set the rear start selector switch to
the OFF position.
2. Remove all belts on left hand alternator,
water pump drive, A/C compressor drive
and alternator drive.
I= IDLER
T= TENSIONER
FIGURE 21: IDLER AND AUTOMATIC BELT TENSIONER
ON ALTERNATOR DRIVE
3. Spin all idler pulleys, I-1 thru I-6, plus the
idlers that are part of the automatic belt
tensioners T-1 thru T-3.
4. Listen if some idlers are noisy and check for
play in the bearings by hand.
5. Replace noisy idlers or if a play is found.
Replace the automatic belt tensioner as a
complete unit.
6. Record the results of the inspection.
4.2 AUTOMATIC BELT TENSIONER
BUSHING WEAR
Automatic belt tensioner bushing wear may
results in belt misalignment.
1. Check the automatic belt tensioner T-1 thru
T-3.
2. Pry the automatic belt tensioner arm and
check for a play between the arm and the
spring case (
FIGURE 22
PA1621 Maintenance Manual All Series | January 2017
24
01234
).
FIGURE 22: CHECKING BUSHING WEAR
3. If bushing wear is suspected, remove the
tensioner. Inspect the tensioner for any
signs of wear. Check for bearing noise as
well as metal to metal contact between the
arm and spring case which is a sign of
bushing wear. Check for cracks in the
tensioner body.
4. Replace the automatic belt tensioner if found
defective.
5. Record the results of the inspection.
4.3 BELTS AND IDLERS VISUAL
INSPECTION
1. Inspect drive belts for cracks, frayed
material, missing
abrasion and peeling. Replace belts if
damaged.
2. Visually inspect all idlers for signs of
deterioration, loose fasteners, etc.
3. Record the results of the inspection.
MAINTENANCE
Visually inspect belts and idlers for signs of
deterioration, cracks, frayed material at the
intervals specified by the Lubrication And
Servicing Schedule
LUBRICATION & SERVICING.

5. ENGINE PROTECTION STRATEGY

The engine protection system will automatically
derate or derate and stop the engine when
certain engine conditions reach a critical stage.
In the event of a serious fault, the red STOP
telltale light comes on and an audible alarm will
sound if the engine is running.
chunks in the belt,
in Section 24: