Komatsu 830E Shop Manual page 361

BRAKE CIRCUIT CHECK-OUT PROCEDURE
The brake circuit hydraulic pressure is supplied from
the steering circuit at the bleed down manifold.
Some brake system problems, such as spongy
brakes, slow brake release, or abnormal operation
of the overhead panel mounted "Low Brake Pres-
sure" warning light can sometimes be traced to
internal leakage of brake components. If internal
leakage is suspected, refer to Brake Circuit Compo-
nent Leakage Test.
1. Rear Brake Accumulator
2. Charging Valve
3. Front Brake Accumulator
4. Park Brake Pressure Reducer
Valve
5. Hoist Pilot Valve
6. Hoist Pilot Manifold
7. Hoist-Up Limit Solenoid
8. Pilot Operated Check Valve
9. Brake Lock Low Pressure
Switch
10. Junction Block
J04031
FIGURE 4-1. HYDRAULIC BRAKE CABINET
11. BF & BR Test Port
(Front & Rear Brake)
12. Stop Light Switch
13. Brake Lock Shuttle Valve
14. Brake Lock Pressure Reducing
Valve
15. Brake Lock Solenoid
16. Park Brake Solenoid
17. Bleed Down Valve
(Front Brake Accumulator)
18. Accumulator Test Port
19. Automatic Apply Valve
Brake Circuit Check-Out Procedure
NOTE: If internal leakage within the steering circuit
is excessive, this also may contribute to problems
within the brake circuit. Be certain that steering
circuit leakage is not
troubleshooting brake circuit. For Steering Circuit
Test Procedure, refer to Section "L", Hydraulic
System.
20. Bleed Down Valve
(Rear Brake Accumulator)
21. Brake Manifold
22. Low Brake Accumulator
Pressure Switch
23. Park Brake Pressure Switch
24. Brake Warning Delay Timer
25. Brake Warning Light Relay
26. Park Brake Test Port
excessive before
J4-1