febi explains a common failure with the switchgear for transmission AND on a water separator for fuel systems.
SWITCHGEAR FOR TRANSMISSION
Function
The switchgear is required to hydraulically actuate the shift valves on the transmission and thus be able to shift the gears in the transmission. It is located below the cabin and the shift lever is directly connected to it. Together with the shift valves on the transmission it forms a closed hydraulic circuit.
Cause of failure
As the switchgear works hydraulically, only a completely vented system can fulfil its function correctly. The hydraulic circuit is often opened during transmission removal, for example when changing the clutch, in order to separate the components.
In this case air can enter the circuit. If the system is not properly vented during assembly, it may not function correctly. In addition, if there is air in the system, the missing center position of the shift lever can cause the shift actuation to move to the left and right stops. This is where valves are located, which can be damaged. Repairs can be carried out using repair kit febi 178726.
WATER SEPARATOR FOR FUEL SYSTEM
Function
A diesel engine cannot function when there is water present in the fuel. In the worst-case scenario, components of the injection system can suffer irreversible damage. To prevent this, water separators are installed in the fuel system. The water separator febi 103487 is located on the underside of the fuel filter. If water collects there, the driver is informed via a display. The water can then be drained from the water separator by means of a solenoid valve.
Cause of failure
Since the water separator is equipped with a sensor and a solenoid valve, electrical contact problems are often the cause of failure. If the water separator is additionally equipped with a fuel heater, the risk of electrical faults is even higher.
