336E Excavator and 336E MHPU Mobile Hydraulic Power Unit Machine Systems Load Control Valve (Boom Cylinder) - Remove and Install Caterpillar

Removal Procedure

Start By:

1. Release the hydraulic system pressure.

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Personal injury can result from hydraulic oil pressure and hot oil. Hydraulic oil pressure can remain in the hydraulic system after the engine has been stopped. Serious injury can be caused if this pressure is not released before any service is done on the hydraulic system. Make sure all of the work tools have been lowered to the ground, and the oil is cool before removing any components or lines. Remove the oil filler cap only when the engine is stopped, and the filler cap is cool enough to touch with your bare hand.

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Cylinders equipped with lock valves can remain pressurized for very long periods of time, even with the hoses removed. Failure to relieve pressure before removing a lock valve or disassembling a cylinder can result in personal injury or death. Ensure all pressure is relieved before removing a lock valve or disassembling a cylinder.

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Illustration 1	g02138737

1. Install Tooling (A) onto the hydraulic tank. Attach an air supply hose onto Tooling (A). Apply 276 to 414 kPa (40 to 60 psi) of air. This procedure will pull vacuum on the hydraulic system.
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   Illustration 2	g01204175

2. Loosen nut (1). Loosen seat (2).
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   Illustration 3	g01204256

3. Disconnect hose assemblies (4) and tube assembly (5). Remove bolts (3).
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   Illustration 4	g01204258

4. Disconnect hose assembly (7).

5. Use two people to remove load control valve (8). The weight of load control valve (8) is approximately 25 kg (55 lb). Remove bolts (6) and load control valve (8).

Installation Procedure

1. Install load control valve (8) in the reverse order of removal.

   1. Tighten seat (2) to a torque of 2 N·m (18 lb in).

   2. Tighten nut (1) to a torque of 4 N·m (35 lb in).