Front Service Brake Conditioning (Burnishing) Procedure; General; Safety Precautions; Front Brake Conditioning - Komatsu 830E-AC Shop Manual

FRONT SERVICE BRAKE CONDITIONING (BURNISHING) PROCEDURE

GENERAL

After any brake lining replacement, or at new truck
start up, the brake linings and discs must be bur-
nished. A surface pyrometer will be necessary to
accurately record disc temperature during brake bur-
nishing procedure.

Safety Precautions

• BEFORE DISCONNECTING
LINES, REPLACING COMPONENTS IN THE
HYDRAULIC CIRCUITS,
TEST GAUGES, ALWAYS BLEED DOWN
HYDRAULIC STEERING
AND BRAKE SYSTEM ACCUMULATORS.
The steering accumulators can be bled down
with engine shut down, turning the key switch
OFF and waiting 90 seconds. Confirm the
steering pressure is released by turning the
steering wheel - No front wheel movement
should occur.
The brake accumulators are bled by opening
the two valves (7, Figure 5-5) on the brake
manifold (inside brake cabinet).
• BEFORE DISABLING ANY BRAKE CIRCUIT,
insure truck wheels are blocked to prevent
possible roll away.
• REAR BRAKES MUST BE DISCONNECTED
WHEN BURNISHING THE FRONT BRAKES.
Front brakes
independently from rear brakes in order to
control disc temperatures
• EXTREME SAFETY PRECAUTIONS SHOULD
BE USED WHEN MAKING HIGH-ENERGY/
HIGH-SPEED BRAKE
DOWNGRADE.
Safety berms or adequate run off ramps are
necessary for any stopping performance
tests.
• Heavy smoke and foul odor from brake
linings is normal
procedures.
J05024 10/06
PRESSURE
OR INSTALLING
ACCUMULATORS
require burnishing
STOPS ON ANY
during burnishing
Rockwell Wheel Speed Front Disc Brakes

Front Brake Conditioning

1. To prevent overheating and possible destruc-
tion of rear brakes, temporarily disconnect the
REAR brakes while burnishing front wheel
brakes as follows:
a. Relieve stored pressure in hydraulic system
according to the previous "WARNING"
instructions.
b. Disconnect "BR" hydraulic tube (1, Figure 5-
5) at both ends inside brake control cabinet.
Install a #8, 0.75 x 16 UNF-2B, 37° flare Cap
Nut (WA2567, or equivalent) on each fitting
where tube was removed. Tighten caps to
standard torque to prevent leakage. Cap or
plug tube to prevent contamination.
NOTE: This will disconnect the hydraulic supply from
the operator's brake pedal to the rear brakes. There
will be a noticeable loss of "braking action" at the
pedal. However, this method of temporarily disabling
the brakes will still permit the application of Brake
Lock, in the event of an emergency.
c. Close brake accumulator bleed valves (7,
Figure 5-5).
2. Drive truck at speeds of 5 to 10 MPH with brake
alternately applied and released using sufficient
pressure to make engine "work" to a noticeable
extent during apply.
NOTE: The Override Switch on the instrument panel
must be depressed and held by the operator in order
to propel with the brakes applied.
3. Apply front brakes at full pressure until discs
reach or just exceed 316° C (600° F). Hold in
override switch to maintain propulsion to obtain
disc temperature. Check temperature after 182
meters (200 yards).
4. Let discs cool to 121° C (250° F) and repeat
procedure two more cycles.
5. Allow front discs to cool to 121° C (250° F).
6. RECONNECT rear brakes:
a. Relieve pressure in hydraulic system accord-
ing to previous "WARNING" instructions.
b. Remove cap nuts and reinstall tube (1).
Tighten tube nuts to standard torque.
c. Close accumulator bleed valve (7) handles.
7. Start engine and check for leaks. Bleed brakes
according to bleeding procedures.
8. Insure all brakes are functioning properly.
J5-9