WABCO iABS 2S/1M Standard, Maintenance Manual

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117
Component Replacement
4. Install the wheel hub carefully, so that the sensor pushes against the tooth wheel as you adjust the
wheel bearings. After installation there should be no gap between the sensor and the tooth wheel.
During normal operation a gap of 0.040-inch is allowable. If the gap is too large, this can cause the
ECU to log a fault code.
5. Sensor Output Voltage Test: Use a volt/ohm meter to check the AC output voltage of the sensors
while rotating the wheel at approximately one-half revolution per second. Minimum output must be
0.2 volts AC, though if the wheel is spun faster than 1/2 of a revolution per second, the reading will
likely be higher. It is important to spin the wheel at the correct speed to determine the output is in fact
correct. If minimum output is less than 0.2 volts AC, push the sensor toward the tooth wheel. Recheck
the sensor output.
7.2 ABS Relay Valve (Figure 7.3)
Fig. 7.3
1002073c
DANGER
Release all pressure from the air system before you disconnect any components. Pressurized air can
cause serious personal injury.
7.2.1 How to Remove a Standard ABS Relay Valve
1. Release all pressure from the air system.
2. Disconnect the cable from the valve.
3. Attach labels to identify all of the air lines.
4. Disconnect the air lines from the valve.
5. Remove the mounting fasteners if the valve is not nipple-mounted directly to the air tank.
6. Remove the valve.