PISTON 4747660 - Caterpillar

TYPICAL GAUGE AND FITTINGS
12. Pressure gauge. 13. 1P2375 Coupler. 14. Coupler. 15. Adapter. 16. Nipple. 17. Tee. 18. Nipple5. Look at the test gauge and operate the electric hydraulic pump. The gauge reading must be 21 700 300 kPa (3150 45 psi).6. If relief valve (11) needs an adjustment, loosen nut (7) and turn screw (8) either clockwise for an increase or counterclockwise for a decrease in the pressure setting of relief valve (11).7. When the pressure setting is correct, tighten nut (7) to a torque of 25 3 N m (18 2 lb. ft.). Remove the test equipment. Install the shroud.
RELIEF VALVE FOR HEAD END OF TILT CYLINDER
7. Nut. 8. Screw.Relief Valves For Attachment Cylinders
Use the same basic procedures to test these line relief valves as is given for the tilt relief valves. The method to read the pressure settings will change according to the optional equipment on the machine.
LOCATION OF PRESSURE TAPS FOR FRONT ATTACHMENTS (TYPICAL EXAMPLE)
LOCATION OF RELIEF VALVES FOR ATTACHMENT CYLINDERS (TYPICAL EXAMPLE)Hydraulic Oil Temperature (Too Hot)
When the temperature of the hydraulic oil gets over 98.8°C (210°F), polyurethane seals in the system start to fail. High oil temperature causes seal failure to become more rapid. There are many reasons why the temperature of the oil will get this hot.1. Hydraulic pump is badly worn.2. Heavy hydraulic loads that cause the main relief valve to open.3. The setting on the main relief valve is too low.4. Too many restrictions in the system.5. Hydraulic oil level in the tank is too low.6. High pressure oil leak in one or more circuits.7. Very dirty oil.8. Air flow through the optional oil cooler core is too low.9. Oil flow through the optional oil cooler is too low.10. Air in the hydraulic oil. If the problem is because of air in the oil, it must be corrected before the system will operate at normal temperatures. There are two things that cause air in the oil (aeration).a. Return oil to the tank goes in above the level of the oil in the tank.b. Air leaks in the oil suction line between the pump and the tank.Bucket Positioner Adjustment Procedure
Make reference to on first page of HYDRAULIC SYSTEM TESTING AND ADJUSTING section.
1. With the engine running, move the tilt control lever to put the bucket at the correct angle to dig. Move the tilt control lever to the HOLD position. Lower the bucket to the ground and stop the engine.2. Make sure that magnet assembly (2) has its longer length perpendicular (in a vertical position) to tube assembly (1). Tighten the set screws in the magnet assembly.3. Measure dimension (A) between magnet assembly (2) and switch assembly (3). The correct dimension is 8 to 12 mm (.3 to .5 in.).4. To change dimension (A), loosen bolts (5) then tighten screw (4) just enough to move tube assembly (1) and the switch away from magnet assembly (2). Switch assembly (3) must be vertically centered with magnet assembly (2).
BUCKET