DUAL RELAY VALVE
The dual relay valves (one for front and one for rear
brake circuits) supply the apply pressure for each disc
brake assembly. When the operator depresses the
brake valve, hydraulic pressure, proportional to the
amount of brake valve application, is applied to the
pilot pressure circuit of each dual relay valve. Regu-
lated pressure (proportional to the pilot pressure ap-
plied) is then delivered from the “B1” and “B2” ports of
each dual relay valve to each wheel.
The regulated pressures supplied to each wheel are
equal. If a malfunction occurs, causing a pressure
differential greater than 300 psi (2068 kPa) between
the right and left brake apply circuit, a differential
pressure switch (3, Figure 3-11) mounted on the valve
activates a warning horn and lamp in the cab. If a
pressure differential greater than 300 psi (2068 kPa)
occurs in the pilot circuit supplying the front and rear
dual relay valves, a differential pressure switch
mounted on the brake valve activates the warning horn
and lamp in the cab.
The dual relay valve for the front brake circuit is located
in the hydraulic components cabinet behind the cab.
The dual relay valve for the rear brake circuit is located
in the rear axle housing and requires removal of the
wheel motor cooling air duct components for access
to the valve as described below.
Before disconnecting pressure lines, replacing
components in the hydraulic circuits, or installing
test gauges, always bleed down hydraulic steering
and brake accumulators. The steering accumula-
tors can be bled down with engine shut down,
turning the key switch “Off” and waiting 90 sec-
onds. Confirm the steering pressure is released by
turning the steering wheel - No front wheel move-
ment should occur.
Open bleed down valves (6 & 7, Figure 3-1) located
on the brake manifold. This will allow both accu-
mulators for the rear brakes and both accumula-
tors for the front brakes to bleed down.
Before disabling brake circuit, be sure truck
wheels are blocked to prevent possible roll-away.
Removal
1. Securely block the wheels to prevent possible
roll-away.
2. Place selector switch in NEUTRAL, turn the rest
switch ON. Turn key switch OFF to shut down
engine and allow 90 seconds for steering system
accumulators to bleed down. Open valves (6 & 7,
Figure 3-1) to bleed down all four brake accumu-
lators. Close valves after all pressure is released.
NOTE: Follow steps 3 & 4 below for the front valve or
steps 5 through 9 for rear valve removal.
Front Brake Circuit:
3. Tag and remove all hydraulic lines from dual relay
valve. Plug lines and ports to prevent possible
contamination. Disconnect wiring harness at dif-
ferential pressure switch connector.
4. Remove two capscrews and washers securing
valve to rear wall of cabinet. Remove valve and
move to clean work area for disassembly.
Rear Brake Circuit:
5. Open rear access cover and remove wing nuts
securing duct tube to axle housing. Remove tube.
6. Open access covers inside axle housing.
7. Remove wheel motor cooling air exhaust duct
from between wheel motors.
8. Tag and remove all hydraulic lines from dual relay
valve. Plug lines and ports to prevent possible
contamination. Disconnect wiring harness at dif-
ferential pressure switch connector.
9. Remove two capscrews and washers securing
valve to mounting bracket. Remove valve and
move to clean work area for disassembly.
Installation.
1. Install dual relay valve in hydraulic components
cabinet (front brake circuit) or rear axle housing
(rear brake circuit). Install the two mounting cap-
screws and lockwashers to secure valve. Tighten
capscrews to standard torque.
2. Remove hose and fitting caps and plugs and
attach hoses to the proper valve ports. Connect
differential pressure switch connector to wire har-
ness.
3. Start engine and check for leaks and proper brake
operation. Shut down engine.
4. For the rear valve, reinstall the wheel motor cool-
ing air duct between wheel motors. Close access
covers and reinstall tube in axle access opening.
J03019 1/99
Brake Circuit Component Service
J3-15
Содержание 930E-2
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Страница 4: ...NOTES ...
Страница 8: ...KOMATSU MODEL 930E Dump Truck A 4 Introduction A00017 03 01 ...
Страница 10: ...NOTES A1 2 Index A01001 2 94 ...
Страница 12: ...930E MAJOR COMPONENTS A2 2 Major Component Description A02055 ...
Страница 35: ...START HERE Walk Around Inspection A03017 General Safety and Operating Instructions A3 21 ...
Страница 46: ...NOTES A3 32 General Safety and Operating Instructions A03017 ...
Страница 78: ...NOTES B1 2 Index B01016 ...
Страница 88: ...NOTES B3 6 Dump Body B03013 03 01 ...
Страница 92: ...NOTES B4 4 Fuel Tank B04015 ...
Страница 94: ...NOTES C1 2 Index C01021 03 01 ...
Страница 118: ...NOTES C5 6 Air Filtration System C05013 5 98 ...
Страница 126: ...NOTES D2 6 24VDC Electric Supply System D02018 ...
Страница 142: ...NOTES D3 16 24VDC System Components D03019 04 01 ...
Страница 146: ...FIGURE 2 1 PROPULSION SYSTEM DIAGRAM E2 2 Electrical Propulsion System Components E02014 3 01 ...
Страница 191: ...FIGURE 2 3 ELECTRICAL CABINET FRONT VIEW E02014 3 01 Electrical Propulsion System Components E2 47 ...
Страница 192: ...FIGURE 2 4 ELECTRICAL CABINET TOP VIEW E2 48 Electrical Propulsion System Components E02014 3 01 ...
Страница 193: ...FIGURE 2 5 ELECTRICAL CABINET REAR FLOOR VIEW E02014 3 01 Electrical Propulsion System Components E2 49 ...
Страница 196: ...NOTES E2 52 Electrical Propulsion System Components E02014 3 01 ...
Страница 240: ...NOTES E3 44 AC Drive System Electrical Checkout Procedure 3 01 E03015 Release 17 Software ...
Страница 242: ...NOTES G1 2 Index G01017 ...
Страница 250: ...NOTES G2 8 Tires and Rims G02015 ...
Страница 274: ...NOTES H1 2 Index H01013 04 01 ...
Страница 282: ...NOTES H2 8 Front Suspensions H02013 2 01 ...
Страница 288: ...NOTES H3 6 Rear Suspensions H03013 ...
Страница 334: ...NOTES J3 32 Brake Circuit Component Service J03019 1 99 ...
Страница 378: ...NOTES L2 8 Hydraulic System L02028 ...
Страница 401: ...FIGURE 4 5 FLOW AMPLIFIER VALVE L04031 Steering Circuit L4 7 ...
Страница 403: ...FIGURE 4 6 FLOW AMPLIFIER NO STEER L04031 Steering Circuit L4 9 ...
Страница 405: ...FIGURE 4 7 FLOW AMPLIFIER LEFT STEER L04031 Steering Circuit L4 11 ...
Страница 407: ...FIGURE 4 8 FLOW AMPLIFIER RIGHT STEER L04031 Steering Circuit L4 13 ...
Страница 409: ...FIGURE 4 9 FLOW AMPLIFIER NO STEER EXTERNAL SHOCK LOAD L04031 Steering Circuit L4 15 ...
Страница 414: ...NOTES L4 20 Steering Circuit L04031 ...
Страница 422: ...NOTES L5 8 Steering Control Unit L05021 ...
Страница 429: ...L06021 Steering Circuit Component Repair L6 7 ...
Страница 450: ...NOTES L6 28 Steering Circuit Component Repair L06021 ...
Страница 466: ...NOTES L7 16 Hoist Circuit L07023 ...
Страница 492: ...NOTES L9 6 Hydraulic System Filters L09008 ...
Страница 504: ...NOTES L10 12 Hydraulic Check out Procedure L10012 ...
Страница 508: ...NOTES M1 2 Index M01034 03 01 ...
Страница 518: ...NOTES M2 3 10 Ansul Checkfire Electric Detection and Actuation System M02003 ...
Страница 524: ...NOTES M5 4 Wiggins Quick Fill Fuel System M05002 10 96 ...
Страница 532: ...NOTES M8 8 Special Tools M08012 9 99 ...
Страница 560: ...NOTES M9 28 Air Conditioning System M09010 6 97 for HFC 134a Refrigerant ...
Страница 575: ...ALTERNATOR PARTS Refer to previous page for Parts List M13003 04 01 Niehoff Alternator Overhaul Manual M13 5 ...
Страница 618: ...M20 20 Payload Meter II M20007 10 00 ...
Страница 619: ...M20007 10 00 Payload Meter II M20 21 ...
Страница 627: ...M20007 10 00 Payload Meter II M20 29 ...
Страница 634: ...NOTES N1 2 Index N01020 03 01 ...
Страница 654: ...NOTES N3 6 Cab Components N03011 7 98 ...
Страница 660: ...NOTES N4 6 Operator Comfort N04020 ...
Страница 686: ...NOTES N5 26 Operator Cab Controls N05044 ...
Страница 688: ...NOTES P1 2 Index P01024 ...
Страница 691: ...P02034 Lubrication and Service P2 3 ...
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Страница 737: ...NOTES R1 2 930E Schematics R01048 with Cummins QSK60 Series Engine ...
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