Komatsu 830E-AC Shop Manual page 586

INITIAL SYSTEM SET-UP
Prior to checking the brake system, the hydraulic
steering system must have proper accumulator pre-
charge and be up to normal operating temperatures.
Refer to Section "L" this manual for steering system
operation procedures and specifications. With the
steering system functioning properly, proceed as fol-
lows:
1. Park truck on a level surface, then turn engine
and key switch OFF. Place wheel chocks on
both sides of all wheels to prevent truck from
moving during this procedure.
2. Fully open each brake accumulator bleeddown
valve and precharge both accumulators to 9653
kPa (1400 psi). Allow gas temperature to
approach ambient temperature before complet-
ing precharge process.
· Record on data sheet.
NOTE: For best performance, charge accumulators
in the ambient conditions in which the machine will
be operating.
3. Close both accumulator bleeddown valves.
4. Install pressure gauges at:
a. Front Brake Test Port "BF" (brake cabinet) -
34,475 kPa (5000 psi) gauge.
b. Rear Brake Test Port "BR" (brake cabinet) -
34,475 kPa (5000 psi) gauge.
c. Low Accumulator Pressure Test Port "LAP1"
(brake manifold) - 34,475 kPa (5000 psi)
gauge.
5. Move directional control lever to PARK position.
Release brake lock.
6. Start engine. Observe rising brake pressures as
system charges. Brake pressure should begin
to fall when Auto Apply Valve releases. Brakes
should release at approximately 14,479 ± 690
kPa (2100 ± 100 psi) front and 10,894 ± 517
kPa (1580 ± 75 psi) rear.
· Record on data sheet.
7. If a brake caliper or brake line was replaced, the
brakes need to bled before proceeding. Partially
depress brake pedal and bleed air from bleed-
ers located at each brake caliper.
J4-6
PARKING BRAKE
NOTE: Move one of the pressure measuring
instruments from the BF or BR locations to the PK2
test port above the Park Brake Solenoid.
8. Actuate brake lock. Move directional control
9. Turn brake lock switch OFF. Measure the lining
If there is no clearance between a brake lining
and the disc, the brake will drag and overheat the
brake components, which may result in reduced
braking capability. Refer to ARMATURE SPEED
REAR DISC BRAKE chapter to service the brake
caliper.
NOTE: If the rear brake calipers were just installed, a
parking brake adjuster may be out of adjustment
which can cause a brake lining to drag. Refer to
ARMATURE SPEED REAR DISC BRAKE chapter to
service the brake caliper.
10. Move directional control lever to PARK.
11. Return the pressure gauge to the BF or BR
Brake Circuit Check-Out Procedure
lever to Neutral. Verify that Park Brake Status
Light indicates parking brake is released. Park
brake release pressure should be 17,238 ± 690
kPa (2500 ± 100 psi).
· Record on data sheet.
to disc clearance with feeler gauge and record
the clearances.
· Record on data sheet.
location from which it was removed.
J04036