 |
|
Personal injury or death can result if two persons are not used in the following procedure. |
|
|
Personal injury or death can result from escaping fluid under pressure. Escaping fluid under pressure, even a very small pin-hole size leak, can penetrate body tissue and cause serious injury and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak. |
| NOTICE |
|---|
|
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting, and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids. Refer to Special Publication, NENG2500, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products. Dispose of all fluids according to local regulations and mandates. |
Reference: For the correct procedure to relieve any hydraulic oil pressure that may be in the steering system, refer to the Service Manual module for Testing and Adjusting, "System Pressure - Release" for the machine that is being tested.
| Required Tools | ||
| Part Number | Description | Qty |
| 1U-5796 | Pressure Differential Tool Gp | 1 |
| 1U-5755 | Hose As | 2 |
| 8T-8902 | Tee | 1 |
| 6v-3965 | Quick Disconnect Coupler | 1 |
| 6V-8397 | O-Ring Seal | 1 |
| 3J-1907 | O-Ring Seal | 1 |
| 6V-0852 | Dust Cap | 1 |
- Move the transmission direction selector to the NEUTRAL position. Engage the parking brake.
Show/hide table
Illustration 1 g06213210 (Typical Example) Standard Location
(4) Pilot supply (Steering)Show/hide table
Illustration 2 g06213224 (Typical Example) Standard Location
(5) Steering pump pressureShow/hide table
Illustration 3 g06212613 (Typical Example) Remote Location (If Equipped)
(4) Pilot supply (Steering)
(5) Steering pump pressure
(6) Rear brake pressure
(7) Front brake pressure
(8) Rear brake accumulator pressure
(9) Left steering cylinder pressure
(10) Right steering cylinder pressure
(11) Brake pump pressure
(12) Front brake accumulator pressureShow/hide table
Illustration 4 g06222228 Typical example of the installation of the differential pressure gauge - Connect to the load sensing pressure tap (4) that connects to the steering pump. The steering pump location is behind the cab and under the platform on left side of machine.
- Connect the high-pressure port (17) of the 1U-5796 Pressure Differential Gauge Group (15) to the quick connect port at the steering pressure (STR-P) port (5) on the diagnostic plate (if equipped). Install a
40000 kPa (5800 psi) pressure gauge (13) at the high-pressure port (14) of the 1U-5796 Pressure Differential Gauge Group. Connect the low-pressure port (16) of the 1U-5796 Pressure Differential Gauge Group (15) to the load sensing pressure tap.Note: While you perform the next steps, do not keep the STIC steering control lever in the LEFT TURN position or in the RIGHT TURN position for more than ten seconds.
- Start the engine. Exercise the steering system in order to increase the hydraulic oil to normal operating temperature. Hydraulic oil temperature of steering system may be monitored advisor disply or the Electronic Technician software.
- The margin pressure is the difference between the pressure of the load sensing line and the pressure of the steering pump output. Margin pressure must be taken while the machine is articulating. With the engine at rated engine speed, give a command to steer to the left or to the right.
- The needle of the differential pressure gauge will bounce between readings, but the needle should stabilize between readings. The correct margin pressure should be
2100 kPa (305 psi) . Adjust the flow compensator valve on the pump control valve if the margin pressure is not correct.
Adjusting the Flow Compensator Valve
- The flow compensator valve is located on the pump control valve. The pump control valve is located on the side of the steering pump. The steering pump is located behind the operator's cab on the left side. The flow compensator valve is nearest to the load sensing line.
- Loosen locknut (8). Turn adjustment screw (18) clockwise in order to increase the margin pressure. Turn adjustment screw (7) counterclockwise in order to decrease the margin pressure.
- When the correct margin pressure is reached, hold the adjustment screw in place and tighten the locknut (19).
- Test the margin pressure again. If the margin pressure is incorrect, repeat Steps 1 through 3.
| |
| Illustration 5 | g06222233 |
|
(18) Adjustment screw
(19) Locknut | |