L322 Range Rover System Description and Operation
BRAKES
DESCRIPTION AND OPERATION
70-15
The ECU is integrated into the hydraulic modulator as one compact unit. This reduces the size and wiring required for
DSC operation. Additionally the motor relay and valve relay have been replaced by solid state final stages in the
control module. The ECU and Hydraulic modulator are available as separate service components. The hydraulic unit
to uses:
l
Two pre-charge solenoid valves
l
Two change over solenoid valves
l
Four intake solenoid valves
l
Four outlet solenoid valves
l
One return pump.
Pre-Charge Pump
1 Cap
2 Bolt
3 Rubber mounting washer
4 Spacer
5 Pre charge pump
6 Bolt
7 Clip
8 Mounting bracket
The pre-charge pump is located adjacent to the brake servo on the inner wing (handed).
At low brake fluid temperature the pre-charge pump removes back pressure from the master cylinder, sucks fluid from
the reservoir and adds it directly into the circuit. The pump is always used for DSC, HDC and ETC operation and is
controlled by the ABS ECU.