267, 277 and 287 Multi Terrain Loaders Machine Systems Caterpillar

Show/hide table

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.

Before any tests are performed, prepare the machine for troubleshooting. Refer to Testing and Adjusting, "Machine Preparation". Before any tests are performed, visually inspect the machine for oil leaks and damaged parts. Refer to Testing and Adjusting, "Visual Inspection".

The pilot system pressure test determines the pressure to the pilot operated hydraulic controls. The pilot oil is supplied by the charge pump section of the gear pump.

1. Engage the parking brake. Stop the engine.

2. Block the wheels of the machine.

3. Raise the cab.

Show/hide table



Illustration 1	g00796641
Photo of front of piston pump for CMP1-699 and CNC1-1199 (1) Charge pressure tap (2) Speed sensing pressure tap

Show/hide table



Illustration 2	g00986299
Photo of front of piston pump for CMP700-UP and CNC1200-UP (1) Charge pressure tap (2) Speed sensing pressure tap

4. Install two 8T-0856 Pressure Gauges to the charge pressure tap (1) and to the speed sensing pressure tap (2) with the 1U-5755 Hoses .

Show/hide table



Illustration 3	g00804712
(3) Supply line for the pilot operated hydraulic control ( work tool)

5. Install a 6V-3965 Nipple to the end of supply line (3) with the 7X-2444 Tee. Use a 6V-5049 O-Ring Seal when you install the tee. Use a 3J-1907 O-Ring Seal when you connect the nipple to the tee. The supply line is for the pilot operated hydraulic control ( work tool).

6. Install the remaining 8T-0856 Pressure Gauge to the nipple that was installed into the tee with the remaining 1U-5755 Hose. This pressure tap is pilot pressure to the pilot operated hydraulic control ( work tool).

7. Secure the three hydraulic lines so that the pressure gauges can be viewed by the operator during the test. The hoses should not be pinched when the cab is lowered.

8. Lower the cab.

9. Sit in the operator's seat. Fasten the seat belt and lower the armrest.

10. Start the engine. Disengage the parking brake.

11. Run the engine at low idle. Record the charge pressure and speed sensing pressure.

12. Run the engine at high idle. Record the charge pressure, speed sensing pressure, and pilot pressure.
    Show/hide table

    Table 2

    PILOT SYSTEM PRESSURES for CMP1-699 and, CNC1-1199
    Pilot Pressure	Low Idle	High Idle
    Charge Pressure	3100 ± 200 kPa (450 ± 30 psi)	3300 ± 200 kPa (480 ± 30 psi)
    Speed Sensing Pressure	1100 ± 200 kPa (160 ± 30 psi)	2550 ± 100 kPa (370 ± 15 psi)
    Pilot Pressure for the Work Tool		3300 ± 200 kPa (480 ± 30 psi)

    Show/hide table

    Table 3

    PILOT SYSTEM PRESSURES for CMP700-UP,, CNC1200-UP, and, CNY1-UP
    Pilot Pressure	Low Idle	High Idle
    Charge Pressure	3200 ± 200 kPa (465 ± 30 psi)	3800 ± 345 kPa (550 ± 50 psi)
    Speed Sensing Pressure	900 ± 200 kPa (130 ± 30 psi)	3200 ± 100 kPa (465 ± 15 psi)
    Pilot Pressure for the Work Tool		3500 ± 200 kPa (510 ± 30 psi)

    Note: If the pilot pressure is not within specifications, refer to Testing and Adjusting, "Hydrostatic System - Test and Adjust".

13. Reduce the engine to low idle. Stop the engine.

14. Raise the cab. Remove the test equipment.

15. Lower the cab. Remove the blocks.