349F and 352F Excavators Hydraulic System Caterpillar

Specification

Introduction

The counterweight relief valve is located in the main pump compartment. The hydraulic activation lever must be in the LOCKED position in order to activate the counterweight removal circuit. Use the following procedure to test the relief valve of the counterweight removal system.

Required Tools

Illustration 1	g02571852
Tooling (A) 198-4240 Digital Pressure Indicator Gp

Machine Preparation

1. Position the machine on level ground.

2. Stop the engine.

3. Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
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   Illustration 2	g02143242
   Pump compartment (1) Pressure tap (delivery pressure for drive pump) (2) Pressure tap (delivery pressure for idler pump) (3) Pressure tap (power shift pressure)

4. Connect a 41,368 kPa (6,000 psi) pressure gauge to pressure tap (2).

Test Procedure

1. Start the engine.

2. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

3. Set the engine speed dial to position "1".

4. Place the hydraulic activation lever in the LOCKED position.
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   Illustration 3	g02383557
   Pump compartment (A) Closed position (B) Open position (4) Switch (5) Ball valves (6) Adjustment screw (7) Locknut (8) Control lever for the counterweight cylinder

5. Place switch (4) in the UP position.

   Note: The engine speed dial will automatically increase to speed dial "2" when counterweight removal device is switched ON.

6. Place ball valves (5) in the OPEN position.

7. Move the control lever for the counterweight cylinder (8) in a downward direction and read the relief valve pressure setting at pressure tap (2). Refer to Table 1 for relief valve specification.

8. Return control lever (8) back to the NEUTRAL position.

Adjustment Procedure

1. In order to adjust the relief valve pressure setting, loosen locknut (7) and turn adjustment screw (6) until the pressure reading is within specification. Refer to Table 1.

   Note: Turning adjustment screw (6) clockwise increases the pressure. Turning adjustment screw (6) counterclockwise decreases the pressure.

   Note: Always make final pressure adjustment on pressure rise.

2. Tighten locknut (7) to a torque of 55 ± 10 N·m (40 ± 7 lb ft).

3. Return switch (4) to the DOWN position. Return ball valves (5) to the CLOSED position.