Page K-8
Repair and Service Manual
B
MECHANICAL BRAKES
Read all of Section B and this section before attempting any procedure. Pay particular attention to Notices, Cautions, Warnings and Dangers.
TROUBLESHOOTING AND
INSPECTION
New Vehicles
A new vehicle will undergo an initial break-in of compo-
nents including brake cables and brake shoes. In this
break-in period, it is not uncommon for the brake pedal
free travel (and the effort required to latch the parking
brake) to change. The timing of this change varies with
terrain and the driving habits of the operators. When this
occurs, the brake linkage should be adjusted. See
“Adjusting Brake Pedal Free Travel” on Page M - 14. After this
initial period, no further adjustments should be required
until routine maintenance is scheduled.
Troubleshooting and Inspection Procedures
To troubleshoot the mechanical brake system, inspect
the brake pedal and linkage to find worn or damaged
parts per the Troubleshooting Table. Then, perform the
Periodic Brake Performance Test to evaluate system
performance. Based on the results of the inspection and
tests, refer to the Troubleshooting Table (Ref. Fig. 5) to
evaluate symptoms and repairs. If required, disassem-
ble the wheel brake to locate and correct internal faults.
Instructions for removal or replacement of parts and
adjustments referred to in this section of the manual are
described
in
detail
under
‘MAINTENANCE
AND
REPAIRS’.
Satisfactory brake performance does not eliminate the
need for routine brake testing and inspection as shown
on the Periodic Service Schedule in Section A. Contin-
ued proper brake operation depends on periodic main-
tenance.
Brake Pedal and Linkage Inspection
1.
Inspect brake pedal return bumper.
Be sure that the brake pedal is contacting the pedal
return bumper when released, that the bumper is in
good condition and that a 1/4 - 3/8" (6 - 9.5 mm) gap
exists between the brake pedal arm and the setscrew
heads of the kick-off cam (Ref. Fig. 6). Replace or
adjust the pedal bumper if required.
Fig. 6 Brake Pedal Bumper Inspection
Fig. 7 Brake Pedal Inspection
2.
Check brake pedal return.
Apply the brake pedal and release.Check that the
brake pedal arm rests against the pedal bumper when
released. If the pedal does not return fully or is slug-
gish, the brake pedal bushings and pivot bolt should
be inspected (Ref. Fig. 7). Replace pedal, spring,
bushings and bolt as required.
3.
Check the brake pedal free travel.
Brake pedal free travel is the distance the pedal
moves from rest to the point at which the brake shoes
first contact the brake drums. This should not be con-
fused with the light resistance that is felt as the brake
pedal is depressed enough to remove slack from the
compensator and cables. Too much pedal free travel
may indicate wheel brakes not adjusting, wear in the
cables and linkages or initial break-in of components.
Not enough pedal free travel may indicate improper
adjustment of the wheel brake or the brake linkage.
1/4" - 3/8" (6 - 9.5 mm) Diameter
Drill or Bolt Must Pass
Through Gap
Adjust At Bumper If Needed
Pivot
Bolt
Brake
Pedal Bushing
Torsion Spring
Brake
Pedal
Arm
Part of
Frame
Содержание EXPRESS L6 2012
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