769D Off-Highway Truck: Relief Valve (Secondary Steering Main) - Test and Adjust

Table 1

Tools Needed	Qty
198-4240 Digital Pressure Indicator	1
198-4239 Pressure Sensor	1

WARNING: Personal injury or death can occur if personnel are trapped between the wheel and the frame. The steering system is hydraulically controlled and wheels can crush personnel during movement.Use caution when working between the wheels and the frame. If the wheels must be turned, ensure that all personnel are clear of the machine before any movement.

BBB1-221, BCA1-172, BDA1-258 and BEC1-201 (1) Brake release and secondary steering pump(2) Plug for the main relief valve on the secondary steering system

The brake release and secondary steering pump is located behind the front bumper.

BBB222-UP, BCA173-UP, BDA259-UP and BEC202-UP (1) Pump and Motor (secondary steering, brake release, prelubrication and high speed oil change -quickevac)(2) Plug for the main relief valve on the secondary steering system

The pump and motor (secondary steering) (brake release) (prelubrication) (high speed oil change - quickevac) is located on the crossmember under the rear of the engine.

The secondary steering and brake release control is located in the cab.

1. Operate the engine at HI IDLE. Turn the steering wheel to the right or turn the steering wheel to the left until the steering cylinder stop is reached. Then, continue turning the steering wheel against the stop. Hold the steering wheel in this position for three seconds and then release the steering wheel. Continue this step until the oil in the steering system reaches at least 38 °C (100 °F).

2. Stop the engine.

3. Place blocks in front of the wheels and behind the wheels.

Note: When the parking brake control is in the ON position, friction from the wheel brakes will not allow the secondary steering system to turn the wheels all the way to the cylinder stops.


4. Turn the parking brake control to the OFF position.

(3) Steering check and relief valve(SS) Pressure tap for the steering system



5. Install the 198-4240 Digital Pressure Indicator with a 198-4239 Pressure Sensor at the pressure tap (SS) for the steering system. Pressure tap (SS) is located on steering check and relief valve (3) behind the right front suspension cylinder.

NOTICE
To minimize battery drain, leave the switch in the MANUAL position only long enough to test the secondary steering. Return the switch to the AUTO position immediately after testing.



6. Use the secondary steering and brake release control in the cab in order to operate brake release and secondary steering pump (1) .

7. Check the pressure on the pressure gauge. The pressure setting of the main relief valve for the secondary steering system is 17225 ± 350 kPa (2500 ± 50 psi).

8. If the pressure needs to be adjusted, remove plug (2) for the main relief valve for the secondary steering system. Use the setscrew that is located behind the plug to change the pressure setting.

9. With an allen wrench, rotate the setscrew clockwise by 1/4 turn in order to raise the pressure. Rotate the setscrew counterclockwise by a 1/4 turn in order to lower the pressure. Each 1/4 turn of the setscrew changes the pressure approximately 1288 kPa (185 psi).

10. Repeat Steps 6 through 9 until the pressure setting is correct.

11. Replace plug (2) for the main relief valve for the secondary steering system and remove the gauge.

MARYGAR

769D Off-Highway Truck: Relief Valve (Secondary Steering Main) - Test and Adjust 2012-12-04T16:50:00-08:00 Rating: 4.5 Diposkan Oleh: Unknown