Komatsu 830E Shop Manual page 396

SERVICE BRAKE CONDITIONING (BURNISHING) PROCEDURE
General
These procedures apply ONLY to the brake lining
assemblies obtained from Komatsu Parts Dept. for use
on Komatsu Electric Drive Trucks equipped with Rock-
well/Goodyear disc brakes.
Conditioning and burnishing of service brake linings
must be performed each time a new set of brake linings
are installed, or before a new Komatsu Truck is put into
operational service. A surface pyrometer is required to
measure brake disc temperatures during the condition-
ing procedures.
If "Brake Certification" type tests are to be run, all lin-
ings and discs should be new and the factory should be
notified. For in-service testing of service brakes, new
linings or discs are not necessary.
Front discs should be in serviceable condition with no
metal smearing or metal buildup from previous use and
not extensively rough or grooved. Inspect discs for
wear limits.
Rear discs will operate at higher temperatures and can
be dark blue in color and show periodic spots [approxi-
mately 1.5 in. (3.8 cm) in size] and still be serviceable.
A disc that is extremely heat-checked with radial cracks
open to show a gap should not be used.
To prevent lining damage during burnishing, as
well as for stop distance tests, release the brakes
as quickly as possible at the end of each cycle or
stop.
The burnish procedure consists of:
1. Alternately applying and releasing the service
brakes until the recommended brake disc surface
temperature is reached: then allow brakes to
cool. Cool brakes, if necessary, by driving
machine. (Rear brakes will normally cool faster
than fronts.) Repeat cycle 3 - 4 more times.
2. To expedite the burnishing cycles of heating and
cooling, operate the brakes on only one axle at a
time, so that the other system will be cooling
(operate front brakes with rear brakes discon-
nected, or rear brakes with front brakes discon-
nected).
3. The recommended order for burnishing is: Front,
Rear, Front, Rear, Front, Rear and Front.
J6-16
Safety Precautions
Rockwell Armature Speed Rear Disc Brakes
• BEFORE DISCONNECTING PRESSURE LINES,
REPLACING COMPONENTS IN THE HYDRAU-
LIC CIRCUITS, OR
GAUGES, ALWAYS BLEED DOWN HYDRAU-
LIC STEERING AND BRAKE ACCUMULATORS.
The steering accumulators can be bled down
with engine shut down, turning the keyswitch
"Off" and waiting 90 seconds. Confirm the
steering pressure is released by turning the
steering wheel - No front wheel movement
should occur. Open the two valves (7, Figure 6-
19) at the bottom of the brake accumulators
(inside brake cabinet) to bleed down the two
brake accumulators.
• BEFORE DISABLING ANY BRAKE CIRCUIT,
insure truck wheels are blocked to prevent
possible rollaway.
• FRONT BRAKES MUST BE DISCONNECTED
WHEN BURNISHING THE REAR BRAKES.
Front brakes require burnishing independently
from rear brakes in order to control disc tem-
peratures
• EXTREME SAFETY PRECAUTIONS SHOULD
BE USED WHEN MAKING HIGH-ENERGY/
HIGH-SPEED BRAKE STOPS ON ANY DOWN-
GRADE.
Safety berms or adequate run off ramps are
necessary for any stopping performance tests.
• Heavy smoke and foul odor from brake linings
is normal during burnishing procedures.
INSTALLING TEST
J06020