Checking Inlet Valves [HD2]

Checking Inlet Valves





- Ignition off.
- Disconnect control module.

Connect a temporary lead between #1 and #34 on test box.
Connect other temporary leads between #20, #38, #54 and #1 on test box.

- Release brake pedal.
- Check that all four wheels can turn freely.

NOTE: When the ignition is switched on, the inlet valves close. To prevent valves overheating, do not leave ignition on for more than 20 seconds. Wait at least 30 seconds before next test.





- Ignition on.
- Push brake pedal down hard as it braking suddenly. Brake pedal should feel stiff and pedal should not travel more than 40 mm (1.57").
- Check that all wheels can turn freely.
- Ignition off.
- Remove temporary leads.

If everything works OK:
- Hydraulic unit valves are OK.

If things do not work properly:
- Try another hydraulic unit as per NE. Hydraulic unit, replacement. Service and Repair