Komatsu PC75UU-2 Excavator Service Manual

Table of Contents

01 GENERAL
10 STRUCTURE AND FUNCTION
20 TESTING AND ADJUSTING
30 DISASSEMBLY AND ASSEMBLY
40 MAINTENANCE STANDARD

GENERAL
This section lists the general machine dimensions, performance specifications, component weights, and fuel, coolant and lubricant specification charts.

STRUCTURE, FUNCTION AND MAINTENANCE STANDARD
This section explains the structure and function of each component. It serves not only to give an understanding of the structure, but also serves as reference material for troubleshooting.

TESTING, ADJUSTING AND TROUBLESHOOTING
This section explains checks to be made before and after performing repairs, as well as adjustments to be made at completion of the checks and repairs. Troubleshooting charts correlating Problems to Causes are also mention in this section.

DISASSEMBLY AND ASSEMBLY KOMATSU Excavator PC75UU-2

This section explains the order to be followed when removing, installing, disassembling or assembling each component, as well as precautions to be taken for these operations.

When raising heavy components, use a hoist or crane. Check that the wire rope, chains and hooks are free from damage.
Always use lifting equipment which has ample capacity. Install the lifting equipment at the correct places. Use a hoist or crane and operate slowly to prevent the component from hitting any other part. Do not work with any part still raised by the hoist or crane.

Manual Extract

Measure the blow-by pressure under the following conditions.

Coolant temperature: Within operating range Hydraulic oil temperature: 45 – 55 C 1. Remove cylinder head cover (1).

2. Install plug E2 to breather tube (2).
3. Install the cylinder head cover, then install blow by pressure gauge E1 to the oil filler port.
4. Run the engine at rated output, and measure the blow-by pressure. A When measuring, be careful not to touch any hot parts or rotating parts. * The blow-by should be measured with the engine running at rated output.

• When measuring in the field, a similar value can be obtained at stall speed.

• If it is possible to check at rated output or stall speed, measure at high idling.

In this case, the blow-by value will be about 80% of the value at rated output. * Blow-by varies greatly according to the condition of the engine. Therefore, if the blow-by value is considered abnormal, check for problems connected with defective blow-by, such as excessive oil consumption, defective exhaust gas color, and prematurely dirty or deteriorated oil.
* After completing the measurement, always be sure to remove plug E2.

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