1 | Tester |
1.1 | Switches |
1.2 | Display |
1.3 | Control wheel |
W46.25-1079-12
Warning | Risk of injury from being trapped in the swivel range of steered axles | Ensure that no persons or objects are in the swivel range of all steered axles when turning the steering wheel. Do not stand in the swivel range of the additional steering axle when the engine is running. | |
Warning | Risk of injury to skin or eyes from hot hydraulic fluid spraying out under high pressure. Risk of burn injuries from contact with components heated by hot hydraulic fluid. Risk of poisoning from swallowing hydraulic fluid | Do not make any technical modifications to the pressure gauge or the test equipment. Check the pressure gauge and test equipment for mechanical damage each time prior to use. Observe the flow diagram when connecting the test equipment. Wear protective gloves, protective clothing and safety glasses. | |
Warning | Risk of accident and injury caused by diagnostic equipment in vehicle while traveling | Never use the test equipment to verify the delivery rate and oil pressure of the power steering pump or the pressure gauge while driving. | |
Warning | Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running. | Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts. | |
Topical note | Notes on maintenance and repair work | ||
Topical note | Notes on handling test equipment for testing delivery rate and oil pressure of power steering pump | ||
Notes on hydraulic fluid as per specification Sheet 345.0 | |||
| Check | ||
1 | Install test equipment (1) in circuit 1. | ||
After bleeding, leave the propeller shaft and the drag links detached and the vehicle jacked up. | |||
2 | Tilt back cab. | Make sure that the test lines are not pinched. | |
3 | Switch on test equipment (1) using switch (1.1) and wait until self-test has been completed. | If the test equipment (1) is not already switched on. | |
During the self-test, all segments in the display (1.2) are actuated briefly. After the self-test, all three green LEDs in the display (1.2) must be lit. If this is not the case, there is a fault in the test equipment (1). Refer to test equipment operator's manual (1). | |||
4 | Turn control wheel (1.3) to left up to end stop. | This ensures that the valve in the test equipment (1) is fully open. | |
5 | Start engine and run at idle speed. | ||
6 | Turn steering left or right and hold at mechanical end stop using normal force of the hand until oil temperature in steering reaches approx. 50 °C. | The oil temperature is the lower value in the display (1.2). | |
7 | Set back pressure of approx. 50 bar. | To do so, turn control wheel (1.3) to right until a pressure of approx. 50 bar is shown in the center of the display (1.2). | |
8 | Check delivery rate. | To do so, read off the upper value in the display (1.2) and compare with the specified value. | |
STEERING GEAR 765.887Power steering pump delivery rate | |||
HEMA dual-circuit power steeringPower steering pump delivery rate | |||
If the delivery rate is not reached. | |||
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Switch off engine and replace power-steering pump. | |||
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9 | Check oil pressure. | | |
The pressure depends on the governed pressure of the pressure limiting valve in the test equipment (1). | |||
STEERING GEAR 765.887Governed pressure of test equipment pressure limiting valve | |||
HEMA dual-circuit power steeringGoverned pressure of test equipment pressure limiting valve | |||
If governed pressure of pressure limiting valve is not reached 3 times in succession in test equipment (1): | |||
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Switch off engine and replace power-steering pump. | |||
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10 | Switch off engine. | ||
11 | Wait until oil temperature drops below 40 °C. | The oil temperature is the lower value in the display (1.2). | |
12 | Switch off test equipment (1). | ||
13 | Remove test equipment (1) from circuit 1. |