HITACHI LX15-7 LX20-7 LX30-7 LX40-7 Wheel Loader Service Manual

1. GENERAL INFOMATION 1-1. Common Items ････････ 1-1-1 1-2. Specifications ･････････ 1-2-1 1

1-1. COMMON ITEMS Scope of Description and Usage of This Manual ･････ 1-1-1 Precautions in Inspection and Service ･････････ 1-1-4 General Precautions for Inspection and Service ･････ 1-1-6 General Precautions for Safety Operation ･････････ 1-1-7 Disassembly and Assembly ････････ 1-1-15 1 – 1

1-1. Common Items 1. General Instructions Scope of Description and Usage of This Manual 1-1-1  To Readers of This Manual This manual provides service staff who have completed basic training with technical information necessary for service activity. For obtaining satisfaction and trust from customers, you are expected to read through this manual and acquire correct product knowledge and service technique.  Reference Material This manual does not, in principle, describe basic items and overlapped areas with other materials (below) to eliminate redundancy. • For basic items, refer to training materials such as "Sales and Technical Material." • For handling and inspection procedures, refer to "Instruction Manual." • For structure and component parts, refer to "Parts Catalog." • For handling, maintenance procedure and parts of the engine, refer to materials issued by the engine manufacturer.  Organization This manual is organized into four parts: 1. General Instructions 2. Construction and Function 3. Oveahaul 4. Troubleshooting 1. General Instructions Safety during maintenance work and general cautionary instructions are compiled. 2. Construction and Function An explanation of the construction and function and an explanation of operation (function) by illustrations, circuit diagrams and system diagrams are compiled. 3. Oveahaul Methods of removing hydraulic equipment from a vehicle, its disassembly and reassembly, its adjusting method, standard values used for service work and service limits are compiled. 4. Troubleshooting Probable causes and corrections for troubles are compiled.

1-1. Common Items 1. General Instructions Scope of Description and Usage of This Manual 1-1-2  Items Listed in This Manual z Page number (3 digit indication) Note) If a page number has a 2 digit indication, the second digit shows the page in each chapter. Equipment code: Refer to the right table. z Position and direction of vehicle Respective positions and directions of a vehicle are indicated in the traveling direction of the vehicle (illustration on the right). z Symbols and notation : Items that require special cautions are indicated in a box to prevent personal injuries or damages to the equipment. DANGER : indicates immediate hazards that WILL result in death or severe injury in a box. WARNING: indicates potential hazards or unsafe practices that COULD result in death or severe injury in a box. CAUTION: indicates potential hazards or unsafe practices that MAY result in minor or medium injury in a box. IMPORTANT: indicates important items for operation and maintenance in a box. NOTE: indicates informative items such as technical information and know-how in a box. : indicates a mass of parts that require caution when held or moved. : indicates a specifically set value (torque) when bolts are tightened. : indicates a volume of discharged water or oil. : indicates a volume of filled water or oil. Equipment Equipment name 0 Engine 1 Electric system 2 Power train I (HST, reduction gear) 3 Power train II (Axle) 4 Brake 5 Steering 6 Frame 7 Hydraulic system 8 Working equipment Right Left Rear Front 2 - 0 - 1 Page in each chapter Number of chapter Equipment code

1-1. Common Items 1. General Instructions Scope of Description and Usage of This Manual 1-1-3 z Indication of Unit In this manual, unit indication of quantity and unit is mainly based on SI (International System) unit system (right table). Example of main unit conversion SI unit (Conventional unit) Pressure 1 MPa (10.197 kgf/cm 2 ) Force 1 N (0.10197 kgf) Torque 1 Nm (0.10197 kgf·m) Power 1 kW (1.360 PS)

1-1. Common Items 1. General Instructions Precautions in Inspection and Service 1-1-4 This section provides the information which is helpful for disassembling and assembling the machine properly and covers the safety precautions and general instructions.  Dust Prevention The most important precaution for maintaininig the longer service life of a machine is to prevent dirt and dust from adhering to the important moving parts. On our produsts, special attention is paid to prevent dirt and dust from getting into each moving part. In a word, an important parts is enclosed and, further, provided with a seal or filter and, thereby, clean air, fule and lubricant are always sent to each part. When disconnecting hydraulic, fuel, lubricating or air pipes and hoses for disassembly, clean each connection and around the connection thoroughly. After disconnectiong the pipes and hoses, immediately cover each opening with a cap, plug or tape to prevent entry of foreign material. When removing an inspection cover or plate also do the same way. Wash and check all parts removed. Check to see that all oil passages and oil holes are not clogged. Cover all parts to prevent dirt and dust from adhering to each part and, when reinstalling each part, check to see that it is clean. On a new part, do not unpack the part until it is installed.  Engine Overhaul Timing For details, refer to the documents supplied by the engine manufacturer.  Precaution for Hydraulic and Pneumatic Systems When impurities such as dirt and dust enter the hydraulic and pneumatic systems, the operation is affected adversely and, further, the parts in the system are damaged excessively to result in the failures of the machine. Accordingly, when the parts in the hydraulic and pneumatic systems have been removed, cover the openings. Further, when pieces of broken metal and rubber have been found in the hydraulic system, flush the whole of the system. Remove and install the parts related to the hydraulic and pneumatic systems in a clean place. Wash all metallic parts in uninflammable safety solvent and coat them with lubricating oil for easier instllation.  Danger Prevention Before servicing the hydraulic system for the working equipments, perform the following steps: (1) Lower all working equipments (bucket, etc.) on the ground. If a working equipment must be removed while holding it in a certain position, refer to “Disassembly and Assembly”. (2) Stop the engine and move each working equipment control lever to all positions to make sure that no pressure is applied to the hydraulic system. (3) Set all control levers to neutral and lock them.  Hydraulic and Pneumatic Valves Check all valves, valve holes and valve seats for scratches and folds. Remove them with a fine oil stone or sand paper. All the valves should move smoothly in their respective holes. Make sure that all passages are free from foregin materials and clean.

1-1. Common Items 1. General Instructions Precautions in Inspection and Service 1-1-5  Hydraulic and Pneumatic Pipes and Hoses When connectiong a metallic pipe, first finger-tighten all bolts and then tighten each end and attaching bracket bolts. After connecting the pipe, connect the hose. At this time, finger-tighten the bolts at both of the hose as a temporary measure. Take care not to allow the hose to come in contact with the parts and other hoses, reduce the bend and twist and then tighten the coupling bolts. A hydraulic hoses has its own bending pattern depending on the manufacturing method. Accordingly, when bending a hydraulic hose for connecting, bend according to the bending pattern. Furhter, when replacing a hose provided with angled stem, assemble and connect with the hose bending pattern fully taken into consideration. After connecting the hoses, proceed as follows: Run the engine and move each control lever to move the working equipments to position. (Refer to “Bleeding Air from Hydraulic System” to be mentioned later.) During that time, observe each hose carefully. Lower the working equipments on the ground, stop the engine and then recondition the twist, interference or excessively hanging, etc. of the hose by turning the stem.  Hydraulic Cylinder The terms for the cylinder have been decided as follows:  Removal of Cylinder When removing each cylinder, it is not required to drain the hydraulic system. Only a small amount of hydraulic oil in the oil passage between the cylinder and control valve flows out. However, when the control lever is not placed in the NEUTRAL position, hydraulic oil will flow out of the tank.  Bleeding Air from Hydraulic System When a hose has been replaced, the hydraulic oil has been changed, a cylinder has been removed and other similar work has been performed, start the engine, move the control levers to move the working equipments to all positions and bleed air in the hydraulic system. After making sure that the hydraulic system operates properly, check the oil level in the tank. NOTE: Run the engine at low idle speed and, in that condition, extend and retract each cylinder about ten times. At this time, do not move the cylinder to the stroke end. When the engine is run at high idle speed and each cylinder is moved to the stroke end from the first, air in the cylinder may damage the seals.  Cleaning the Hydraulic Brake System Use the specified brake fluid. If other brake fluid is used, a rubber part may be deteriorated and swollen. When adjusting the hydraulic brake system, take care not to allow foreign material to get into the brake fluid. To wash the master cylinder, wash in general part washing agent and then wipe the trace of solvent with denatured alcohol or brake fluid. After that, dry the cylinder and take care not to allow dirt and dust to adhere to the cylinder until it is assembled. Wash rubber parts in denatured alcohol or brake fluid. Do not use solvent of petroleum series, such as gasoline, kerosene, acetone, paint thinner, which will soften and swell a rubber part. Rod End (Part) Cylinder Head (Part) Tube End (Part) Cylinder Bottom (Chamber) Rod (Chamber)

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HITACHI LX15-7 LX20-7 LX30-7 LX40-7 Wheel Loader Service Manual

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