Brake System 1

T6 rev1.2 02.06 MY
Main components

Sandvik Mining and Construction

 Brake System 2
T6 rev1.2 02.06 MY
System description

Pressure from a converter mounted double pump enters via high pressure filter Z306 to
the brake charging valve V312 where the brake changing pressure is regulated to the proper working range.
When brake charging pressure is over certain limit, excessive flow from sequence valve is directed to the brake
flushing circuit.
The symbol to the right of the main window shows the status of the charging pressure of the brakes. The symbol
is grey when the charging pressure is under the limit, and becomes darker when the charging pressure is above
the limit.

Sandvik Mining and Construction

 Brake System 3
T6 rev1.2 02.06 MY
Brake system

Service brake
The machine is equipped with a double circuit brake system. These circuits are controlled by brake pedal
valve V105. When pressing the brake pedal, pedal valve prevents oil pressure to enter the wheel brakes.
From wheel brakes oil flows through brake charging valve, via pedal valve back to tank and brakes activates.
Front and rear axles have separate circuits. When pedal is released, pedal valve lets oil flow through the
brake charging valve to wheel brakes releasing the brakes.

Emergency brake system

The emergency brake functions with the same valves as the service and parking brakes.
Activating the emergency stop disconnects the control signals that controls engine, steering and brakes.

Charging the pressure accumulator

Charging of the pressure accumulators is only possible in operational mode (ignition key S004 is in position
“1” and the engine is running).

Discharging the pressure accumulators

Brake pressure accumulator is discharged when ignition key S004 is turned to position “0”, in other words
when the engine is switched off.
Valve Y352 is not energized when ignition key S004 is turned to position “0” and the drain line opens.

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 Brake System 4
T6 rev1.2 02.06 MY
Brake system

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 Brake System 5
T6 rev1.2 02.06 MY
Brake system

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 Brake System 6
T6 rev1.2 02.06 MY
Brake release

Sandvik Mining and Construction

 Brake System 7
T6 rev1.2 02.06 MY
Brake release / unloading

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 Brake System 8
T6 rev1.2 02.06 MY
Service brake

Sandvik Mining and Construction

 Brake System 9
T6 rev1.2 02.06 MY
Electric diagram
CB1.0 CB1.1
5/26 18/16

1 14 12
F006
10A
2 11

9
S006
BRAKE 2 1 0 1 3 1 3 X2
X154 18
RELEASE
SWITCH
2 4 2 4 X1 X154 X154
GND0.1
10
10 12 Interlock 124
X154 5 7 19 7 6 Brake valve control (XM1:7) 3 – module system:
X41 X41 Output is active and release the parking brake when:
XM1 XM1
X154 X154 X154 MIDDLE - Emergency stop not active (button not pressed down)
in 124 in
MODULE - Engine is running
X41 X41 6 X154 8 20 XM2 24/22 XM3 - Door is closed
X154
11 13 - Hydraulic oil or brake oil alarms not active
19
E-RADIO E-RADIO
X154
17 - ABA control not on
X155 X155
2 3 21 - Neutral brake control not on
If brake release pump is activated, emergency stop
may not be on
1

4 5 1 4 5 1 4 5 1 3 1 4 5 1 +24v
J305.9
K037A K037B K035 K036 K025 10/24

3 2 3 2 3 2 4 5 2 3 2
GND GND
JGND18 JGND16
13/23 16/13

22 24
X118 X118
0 1 3 1 6 4 8
BRAKE CIRCUIT 1
1 1 6 7 BRAKE
X148 X148 1 JARRUPIIRI 1
RELEASE PUMP
Y301 Y348 +24V
S053 2 5 7
2 2 J623.4
6/23 BRAKE CIRCUIT 2
X118 X118 11/11 J623.3 2
23 25 JARRUPIIRI 2
X154 X154 10/24 JGND6
X154 X154 13 14 BRAKE RELEASE PUMP SWITCH
11 12 3 JARRUN VAPAUTUSPUMPPU

GND0.1 GND0.1
1 2 3
3-56010890-14

Sandvik Mining and Construction

 Brake System 10
T6 rev1.2 02.06 MY
Electric diagram/stand-by
CB1.0 CB1.1
5/26 18/16
-Brake not released. Brake release
1 14 12
F006
10A
button in position 0
2 11
-Engine running
9 -Door closed
S006
BRAKE 2 1 0 1 3 1 3 X2
X154 18
RELEASE
SWITCH
2 4 2 4 X1 X154 X154
GND0.1
10
10 12 Interlock 124
X154 5 7 19 7 6 Brake valve control (XM1:7) 3 – module system:
X41 X41 Output is active and release the parking brake when:
XM1 XM1
X154 X154 X154 MIDDLE - Emergency stop not active (button not pressed down)
in 124 in
MODULE - Engine is running
X41 X41 6 X154 8 20 XM2 24/22 XM3 - Door is closed
X154
11 13 - Hydraulic oil or brake oil alarms not active
19
E-RADIO E-RADIO
X154
17 - ABA control not on
X155 X155
2 3 21 - Neutral brake control not on
If brake release pump is activated, emergency stop
may not be on
1

4 5 1 4 5 1 4 5 1 3 1 4 5 1 +24v
J305.9
K037A K037B K035 K036 K025 10/24

3 2 3 2 3 2 4 5 2 3 2
GND GND
JGND18 JGND16
13/23 16/13

22 24
X118 X118
0 1 3 1 6 4 8
BRAKE CIRCUIT 1
1 1 6 7 BRAKE
X148 X148 1 JARRUPIIRI 1
RELEASE PUMP
Y301 Y348 +24V
S053 2 5 7
2 2 J623.4
6/23 BRAKE CIRCUIT 2
X118 X118 11/11 J623.3 2
23 25 JARRUPIIRI 2
X154 X154 10/24 JGND6
X154 X154 13 14 BRAKE RELEASE PUMP SWITCH
11 12 3 JARRUN VAPAUTUSPUMPPU

GND0.1 GND0.1
1 2 3
3-56010890-14

Sandvik Mining and Construction

 Brake System 11
T6 rev1.2 02.06 MY
Electric diagram/Brake release step 1
CB1.0 CB1.1
5/26 18/16
-Brake release button is
1 14 12
F006
10A
pulled up (pos2)
2 11
-Engine running
9 -Door closed
S006
BRAKE 2 1 0 1 3 1 3 X2
X154 18
RELEASE
SWITCH
2 4 2 4 X1 X154 X154
GND0.1
10
10 12 Interlock 124
X154 5 7 19 7 6 Brake valve control (XM1:7) 3 – module system:
X41 X41 Output is active and release the parking brake when:
XM1 XM1
X154 X154 X154 MIDDLE - Emergency stop not active (button not pressed down)
in 124 in
MODULE - Engine is running
X41 X41 6 X154 8 20 XM2 24/22 XM3 - Door is closed
X154
11 13 - Hydraulic oil or brake oil alarms not active
19
E-RADIO E-RADIO
X154
17 - ABA control not on
X155 X155
2 3 21 - Neutral brake control not on
If brake release pump is activated, emergency stop
may not be on
1

4 5 1 4 5 1 4 5 1 3 1 4 5 1 +24v
J305.9
K037A K037B K035 K036 K025 10/24

3 2 3 2 3 2 4 5 2 3 2
GND GND
JGND18 JGND16
13/23 16/13

22 24
X118 X118
0 1 3 1 6 4 8
BRAKE CIRCUIT 1
1 1 6 7 BRAKE
X148 X148 1 JARRUPIIRI 1
RELEASE PUMP
Y301 Y348 +24V
S053 2 5 7
2 2 J623.4
6/23 BRAKE CIRCUIT 2
X118 X118 11/11 J623.3 2
23 25 JARRUPIIRI 2
X154 X154 10/24 JGND6
X154 X154 13 14 BRAKE RELEASE PUMP SWITCH
11 12 3 JARRUN VAPAUTUSPUMPPU

GND0.1 GND0.1
1 2 3
3-56010890-14

Sandvik Mining and Construction

 Brake System 12
T6 rev1.2 02.06 MY
Electric diagram/Brake release step 2
CB1.0 CB1.1
5/26 18/16
-Brake release button is released
1 14 12
F006
10A
back to middle position (pos1)
2 11
-Engine running
9 -Door closed
S006
BRAKE 2 1 0 1 3 1 3 X2
X154 18
RELEASE
SWITCH
2 4 2 4 X1 X154 X154
GND0.1
10
10 12 Interlock 124
X154 5 7 19 7 6 Brake valve control (XM1:7) 3 – module system:
X41 X41 Output is active and release the parking brake when:
XM1 XM1
X154 X154 X154 MIDDLE - Emergency stop not active (button not pressed down)
in 124 in
MODULE - Engine is running
X41 X41 6 X154 8 20 XM2 24/22 XM3 - Door is closed
X154
11 13 - Hydraulic oil or brake oil alarms not active
19
E-RADIO E-RADIO
X154
17 - ABA control not on
X155 X155
2 3 21 - Neutral brake control not on
If brake release pump is activated, emergency stop
may not be on
1

4 5 1 4 5 1 4 5 1 3 1 4 5 1 +24v
J305.9
K037A K037B K035 K036 K025 10/24

3 2 3 2 3 2 4 5 2 3 2
GND GND
JGND18 JGND16
13/23 16/13

22 24
X118 X118
0 1 3 1 6 4 8
BRAKE CIRCUIT 1
1 1 6 7 BRAKE
X148 X148 1 JARRUPIIRI 1
RELEASE PUMP
Y301 Y348 +24V
S053 2 5 7
2 2 J623.4
6/23 BRAKE CIRCUIT 2
X118 X118 11/11 J623.3 2
23 25 JARRUPIIRI 2
X154 X154 10/24 JGND6
X154 X154 13 14 BRAKE RELEASE PUMP SWITCH
11 12 3 JARRUN VAPAUTUSPUMPPU

GND0.1 GND0.1
1 2 3
3-56010890-14

Sandvik Mining and Construction

 Brake System 13
T6 rev1.2 02.06 MY
Parking brake (Three-module systems)

You can release the parking brake by pulling the button up. You can engage the brake by pressing the button
down. The control system controls voltage going to the safety relay. If the parking brake releasing conditions
are fullfilled then and only then will the brakes be allowed to be released. The parking brake is controlled with
the solenoid valves fitted to the brake charging valve. When the solenoid valves are deenergized, oil flow is
directed from the brake circuit via the brake charging valve to the tank and the parking brake activates. When
releasing the parking brake, the solenoid valves are energized. The oil flows from the pressure accumulator via
brake charging valve to the brake circuit.
If the parking brake is engaged because of a malfunction (such as low transmission oil pressure, ABA), the
button might already be in the released position, in this case it is necessary to reset the parking brake button.
The parking brake will engage in following conditions:
•when the button is pressed in
•when the engine is turned off
•when the door is opened
•when the emergency stop is activated.

The symbol to the right of the main display window and the indicator light on the parking brake button. The
symbol is grey when the parking brake is released, and becomes darker when the parking brake is engaged.

Sandvik Mining and Construction

 Brake System 14
T6 rev1.2 02.06 MY
Parking brake (Three-module systems)

The conditions that allows the service/ parking brake to be

released are as follows:
- Emergency stop is not active
- The engine is running
- The door is closed
- The lower limit alarm for the hydraulic oil is not activated
- The lower limit alarm for the hydraulic oil for brakes is not
activated
- ABA is not active
- The neutral brake is not active

Sandvik Mining and Construction

 Brake System 15
T6 rev1.2 02.06 MY
Parking brake (Five-module systems)

Control the parking brake with the mushroom-shaped button in the cabin, the button is connected to the
Dashboard module. The button has three positions: brake engaged, brake released, and resetting (returns
automatically with a spring). The brakes are controlled with proportional hydraulic valves that is connected to
the Middle and Rear modules. The brakes are engaged when there is no current going to the valves (button is
pushed in). When the parking brake is engaged, it can only be released after the button has been pulled out
into the releasing position. The brake are released only when both inputs of the button are active. The brakes
stay released only when the button is held in the relesed position until feedback information comes from the
pressure sensor in the brake circuits.
If the parking brake is engaged because of a malfunction (such as low transmission oil pressure, ABA), the
button might already be in the released position. In this case is necessary to reset the parking brake button.
The parking brake will engage in following conditions:
-when the button is pressed in
-when the engine is turned off
-when the door is opened
-when the emergency stop is activated.

The symbol to the right of the main display window and the indicator light on the parking brake button tells the
status of the parking brake. The symbol is grey when the parking brake is released, and becomes darker when
the parking brake is engaged.

Sandvik Mining and Construction

 Brake System 16
T6 rev1.2 02.06 MY
Parking brake (Five-module systems)

The conditions that allows the service/ parking brake to be

released are as follows:
- Emergency stop is not active
- The engine is running
- The door is closed
- The lower limit alarm for the hydraulic oil is not activated
- The lower limit alarm for the hydraulic oil for brakes is not
activated
- ABA is not active
- The neutral brake is not active

Sandvik Mining and Construction

 Brake System 17
T6 rev1.2 02.06 MY
Service- and parking brake inputs/outputs

Service- and parking brake inputs

Service- and parking brake outputs

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 Brake System 18
T6 rev1.2 02.06 MY
Functional description of components

Brake charging valve V312

When pressure at the brake accumulator decreases, brake charging
valve begins to charge the accumulator. Charging continues until
pressure at the accumulator is 190 bars. Brake charging valve contains
also pressure relief valve, which limits the hydraulic pressure of the
brake circuit to a maximum of 230 bars.

Pressure transducer B357 (1.)

Pressure transducer B357 measures the hydraulic pressure of the rear
brake.

Pressure transducer B356 (2.)

Pressure transducer B356 measures the hydraulic pressure of the front
brake.

Pressure transducer B334 (3.)

Pressure transducer B334 measures the brake charging pressure.

Sandvik Mining and Construction

 Brake System 19
T6 rev1.2 02.06 MY
Functional description of components

Solenoid valve Y352 (4.)

Solenoid valve Y352 controls discharging pressure of the pressure
accumulator Z205. When the ignition switch is turned to “0”
position, solenoid valve Y352 deactivates and pressure
accumulator oil drains to hydraulic oil receiver via solenoid valve.

Solenoid valve Y348 (5.) Solenoid valve (5) Y348 controls the rear
brake circuit. When the valve is energized, hydraulic line from the
pressure accumulator is open. Oil flows through magnetic valve
Y348 to rear brake circuit which releases the front wheel brake.

Solenoid valve Y301 (6.)

Solenoid valve (6) Y301 controls the front brake circuit. When the
valve is energized, hydraulic line from the pressure accumulator is
open. Oil flows through magnetic valve Y301 to front brake circuit
which releases the front wheel brake.

Sandvik Mining and Construction

 Brake System 20
T6 rev1.2 02.06 MY
Functional description of components

Sequence valve V308

Sequence valve V308 is composed of two valves: a pilot operated sequence
valve and a fixed throttle valve(Not used in this machine). The sequence valve
directs oil flow to brake charging valve if needed. A spring force of the
sequence valve spool defines brake charging volume flow.

Brake pedal valve V105

When machine is running and the brake pedal is in the rest position, the
pressure in the hydraulic control line behind the
pedal is 120 bar. When pressing the brake pedal, it connects hydraulic control
line of brakes to the tank line proportionally.

pictures for
1 st unit only

Sandvik Mining and Construction

 Brake System 21
T6 rev1.2 02.06 MY
Functional description of components

Filter unit Z306

Pressure filter (1)

The pressure filter cleans the hydraulic oil going to the brake charging
valve. Filtration efficiency β10=75.

Limit switch S378 (2)

Limit switch S378 indicates blockage of the filter.

Spring-loaded non-return valve

The non-return valve lets the hydraulic oil going to the brake valve past the
filter when the filter’s primary pressure is more than 5 bar greater than the
filter’s
secondary pressure.

Sandvik Mining and Construction

 Brake System 22
T6 rev1.2 02.06 MY
Functional description of components

Brake release pump unit

If the machine breaks down, the pressure needed for releasing the brakes
can be produced with a special brake release pump.
Start the pump from the button in the cabin, the parking brake button must
be in the release position. The pump stays on until you release the button.
When using the brake release pump, the engine must not be running and
the emergency stop must not be activated. When using this function, it will
be recorded in the alarm log.
Pump unit A310 (1.)
In the case of engine, pump or charging valve breakdown, the electric
pump A310 can provide enough pressure to release the brakes. The
pump is powered by electric motor M320.
Pressure relief valve V309 (2.)
The pressure relief valve limits the pressure to 210 bar on the pressure
side of the pump unit.
Limit switch S348 (3.)
Limit switch S348 indicates the brake accumulator pressure. This switch
stops the brake release pump when the pressure is more than 140 bar.
Non-return valve (4.)
Does not allow the capacity of pressure accumulator Z205 to flow to the
pressure side of brake release pump unit A310.

Sandvik Mining and Construction

 Brake System 23
T6 rev1.2 02.06 MY
Functional description of components

Pressure accumulator Z205

The accumulator volume is 6,0 l and the pre-charge
pressure is 90 bar.When the external
pressure in the line is over 90 bar, the accumulator charges,
or in other words stores
hydraulic energy (oil+pressure). If the external pressure in
the line falls, for example when brake pedal V015 has
pressed, the accumulator discharges, or releases the
hydraulic oil and pressure it has stored.

Sandvik Mining and Construction

 Brake System 24
T6 rev1.2 02.06 MY
Pressure accumulators

General
Under no circumstances may any machining, welding or soldering work be done on the accumulator shell. Work on
systems incorporating accumulators (repairs, connection of pressure gauges, etc.) may be carried out only after the
fluid pressure has been released. New or reconditioned accumulators are delivered with a nitrogen charge of 1,0
MPa (10 bar) to prevent damage during transit. Before being put into operation they must be charged with nitrogen
to the pre-charge pressure. The brake accumulators pre-charging pressure is 90 bar (9,0MPa). Under NO
circumstances should oxygen or air be used.

Having connected the hydraulic line, it should be bled of all air by means of bleeder screw on the accumulator.
Never use car tire valves to replace damaged gas valve elements.

Sandvik Mining and Construction

 Brake System 25
T6 rev1.2 02.06 MY
Brake flushing

Sandvik Mining and Construction

 Brake System 26
T6 rev1.2 02.06 MY
Brake flushing System description

When the pressure accumulator Z205 pressure is adequate, excessive flow from
sequence valve V308 is directed to brake flushing circuit and then to the tank through a non-return valve. This
valve has an opening pressure of 1,0 bar (100 kPa) and flow is forced to the wheel brake cooling system.
Equal amount of oil will flow to the front and rear axle brakes. The oil flow to each brake chamber is mainly
controlled with hose and fitting sizing. Return flow from each brake chamber is directed back to hydraulic oil
tank through return filter Z307.
The return filter has a by-pass valve in case the filter gets clogged. The opening pressure for By-pass valve is
0,4 bar.

Sandvik Mining and Construction

 Brake System 27
T6 rev1.2 02.06 MY
Functional description of components

Filter unit Z307 (1.)

Return filter
The return filter cleans the hydraulic oil returning from brake flushing to hydraulic
oil receiver. Filtering efficiency is β20=75.

Spring-loaded non-return valve

The non-return valve lets the hydraulic oil returning to the hydraulic oil receiver
past the filter when the filter’s primary
pressure is more than 0,4 bar greater than the filter’s secondary pressure. (See
also Chapter General hydraulics, section Filter diagnostics).

Filter limit switch S376 (2.)

Limit switch S376 indicates blockage of the filter. See also chapter “General
hydraulics” section “Filter diagnostics”.

Sequence valve V308

See the description for brake system components.

Spring-loaded non-return valve (1.)

The spring-loaded non-return valve allows the brake oil returning to the hydraulic
oil receiver to flow straight to
the receiver past the brake cooling circuit, when the cooling circuit pressure is
more than 1.0 bar greater than the pressure on the secondary side.

Sandvik Mining and Construction

 Brake System 28
T6 rev1.2 02.06 MY
ABA (Automatic Brake Activation)

ABA stands for automatic brake activation during malfunctions.

Five-module systems
ABA engages the parking brake with a parameter-defined ramp (enables slow braking) in the following situations:
- The accumulator pressure for brakes (Brake circuit actual pressure front or rear) falls below the alarm limit (see
section ”Measuring the brake pressures”).
- The transmission pressure (TransmissionOilPressure) falls below the alarm limit (see Chapter Power train,
section ”Measuring the transmission pressure”).
- The door opens during driving.
-If there is a active Control valve fault.
-If the control valve fault is deactivated within the time period set with a parameter, then brake will be
released automatically.
- If the brake is engaged over a time period set with a parameter, the brake will not be released
automatically.
After these situations, the operator must release the parking brake with the button.

Three-module systems
The brakes have similar ABA function than the five-module systems. The only exception is that there is no
deceleration ramp.

Sandvik Mining and Construction

 Brake System 29
T6 rev1.2 02.06 MY
Gauge window for brake pressures

The following data from the brake pressure sensors is shown in gauge window 3:
- Brake circuit charging pressure
- Brake pedal pressure
- Brake circuit 1 actual pressure
-Brake circuit 2 actual pressure
The alarm and warning limits for the sensors are shown on the information window.
Active alarms and warnings are shown with the following symbols on the gauge window (the symbols
appear on the left hand side of the symbol for the sensor).

Sandvik Mining and Construction

 Brake System 30
T6 rev1.2 02.06 MY
Diagnostics

The diagnostics data of the window:

- The control status of the module is shown below the module
symbol: 0 = the program does not control the parking brake on, 1
= the program controls the parking brake on
- The charging pressure of the brakes is shown next to the brake
symbol at the top of the window (charge)
- The pressure of the front brake circuit is shown next to the
brake symbol in the middle (actual 1)
- The pressure of the rear brake circuit is shown next to the
lowest brake symbol (actual 2)
The information window shows the lower limit for charging
pressure of brake releasing.

Sandvik Mining and Construction

 Brake System 31
T6 rev1.2 02.06 MY
Checking and adjusting

Measuring the brake accumulator pre-charge pressure (90 bar) without filling device

Measure the gas pre-charge pressure (90 bar) by measuring the hydraulic
fluid pressure with a pressure gauge.
1. Connect a 250 bar pressure gauge to the test nipple in the brake
accumulator. Use hose long enough to read the gauge while sitting in the
cabin.
2. Start the engine to fill the accumulator with fluid.
3. Stop the engine by turning the ignition key to the “0” position, so the
pressure accumulator discharges to tank through a orifice. During this
emptying process watch the pressure gauge carefully.
4. As soon as the accumulator pre-charge pressure 90 bar (9,0 MPa) is
reached, the pressure will drop suddenly back to zero.
5. If the pre-charge pressure is too low, the accumulator must be
recharged with nitrogen.

Sandvik Mining and Construction

 Brake System 32
T6 rev1.2 02.06 MY
Checking and adjusting
Measuring brake pressures
The brake circuit has 3-4 analog sensors, depending on the amount of the modules. The system gives an
alarm if the sensor signals are not within the calibrated values.
The charging pressure of the brakes is measured with an analog sensor that is connected to the Middle
module. The system gives an alarm, if the signal differs from the calibrated values.

Inputs

Outputs

Sandvik Mining and Construction

 Brake System 33
T6 rev1.2 02.06 MY
Checking and adjusting

Testing the brake accumulator

After new installation of, or repair to accumulators, check pre-charge
pressure p0 at least once during the first month.
If no gas losses are detected during the first check, the second check is
to be carried out after approx. 6 months. If the results of the second
check are satisfactory, testing every 6:th month will suffice thereafter.

Sandvik Mining and Construction

 Brake System 34
T6 rev1.2 02.06 MY
Recharging piston accumulators

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 Brake System 35
T6 rev1.2 02.06 MY
Neutral brake (option)

The neutral brake prevents driving the machine downhill on neutral gear. The neutral brake engages the parking
brake when the gear has been on neutral for a time period defined with a parameter (the default value is 3
seconds). When the operator releases the parking brake, he has to switch a gear on within a time period.
A window appears on the display that informs that the neutral brake is activated. The neutral brake is not
activated when the brake pedal is pressed (the brake lights are lit).
The DeClutch function can be use for a time period (the default value is 10 seconds).
When the DeClutch function is released, the timer is reset.
The neutral brake will be engaged if the operator does not perform one of the following
actions within a time period set with a parameter:
- Switch on a gear.
- Press the brake pedal.
- Press the DeClutch button.
The neutral brake will be released in the same way as the parking brake.

Sandvik Mining and Construction

 Brake System 36
T6 rev1.2 02.06 MY
Neutral brake (option)

Inputs

Outputs

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