Hydraulic & Mechanical Troubleshooting Guide: Seat Machine Group 2 (EN)

GROUP 2 HYDRAULIC AND MECHANICAL SYSTEM 1. INTRODUCTION 1) MACHINE IN GENERAL (1) If even a minor fault is left intact and operation is continued, a fatal failure may be caused, entailing a large sum of expenses and long hours of restoration. Therefore when even a small trouble occurs, do not rely on your intuition and experience, but look for the cause based on the troubleshooting principle and perform maintenance and adjustment to prevent major failure from occurring. Keep in mind that a fault results from a combination of different causes. (2) The following lists up commonly occurring faults and possible causes with this machine.

For the troubleshooting of the engine, refer to the coming troubleshooting and repair. (3) When carrying out troubleshooting, do not hurry to disassemble the components. It will become impossible to find the cause of the problem. (4) Ask user or operator the following. Was there any strange thing about machine before failure occurred? Under what conditions did the failure occur? Have any repairs been carried out before the failure? ① ② ③ (5) ① ② ③ Check before troubleshooting. Check oil and fuel level. Check for any external leakage of oil from components. Check for loose or damage of wiring and connections. 6-4

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2. DRIVE SYSTEM UNUSUAL NOISE COMES OUT OF PUMP CONNECTION 1) YES Remove dust plug under engine flywheel and check if rubber pieces or particles are not present. YES 6-5 Cause Remedy Coupling element is broken. Disassemble and repair. Replace hub or retighten setscrew. Coupling hub spline is worn or NO hub fastening setscrew is slack. If hydraulic pump or engine is NO suspected as a culprit refer to this manual "Structure and function".

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ENGINE STARTS BUT MACHINE DOES NOT OPERATE AT ALL 2) Is oil level in hydraulic oil tank within standard level? 6-6 NO Cause Remedy Hydraulic pump is broken. ⓐ Pilot valve is faulty. Pilot relief valve is faulty. Gear pump is broken. Replenish specified oil to the standard level. Disassemble and repair. See item 1). at page 6-5 Clean pilot piping interior or repair piping. Disassemble and repair. Repair or replace. Disassemble and repair. Abnormal noise YES YES comes out of hydraulic pump Do not hydraulic pump and pump YES Abnormal noise YES hydraulic pump S Abnormal noise YES Do not hydraulic pump and pump Abnormal noise YE S connections comes out of S make abnormal pump connection noise?

Is primary pilot pressure within NO standard level? YES Is not pilot piping YES clogged or is not oil leakage present on pilot piping? NO ⓐ YES Is gear pump delivering oil? NO NO connections make abnormal noise? comes out of pump connection Is primary pilot pressure within comes out of pump connection

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3. HYDRAULIC SYSTEM HYDRAULIC OIL IS CLOUDY 1) HYDRAULIC OIL TEMPERATURE HAS RISEN ABNORMALLY 2) 6-7 YES Drop hydraulic oil sample on hot plate and check if foams come up. NO Cause Remedy Water is mixed. Air is intruded. Put hydraulic oil still, separate water and dispose it or replace hydraulic oil. Check suction line and return line and eliminate the air intruding source. NO Is hydraulic oil volume proper? YES Is not oil cooler clogged and is YES anything blocking YES air circulation? Is fan belt NO tension proper? NO Is not the set YES pressure of main relief, relief and ⓐ travel relief valve Is main relief lower than the valve used very YES NO standard level? often?

Cause Remedy ⓐ Replenish specified oil to the standard level. Clean oil cooler. Secure air circulation route. Adjust belt tension or replace belt. Readjust set pressure. Reduce load. Is main relief valve used very YES Is main relief valve used very often?

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