ST-45HRM CE CONCRETE PUMP—TROUBLESHOOTING (HYDRAULIC
Practically all breakdowns can be prevented by proper handling and maintenance inspections, but in the event of a breakdown, please take a remedial action following the diagnosis based on the Hydraulic System Troubleshooting (Table 15) information shown below and on the proceeding page. If the problem cannot be remedied, please leave the unit just as it is and consult our company's business office or service plant.
TABLE 15. HYDRAULIC SYSTEM TROUBLESHOOTING
SYMPTOM | POSSIBLE PROBLEM | SOLUTION | |
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| Check TB1 terminal #17. If this terminal is energized when the | |
| Delta "Q" compensator not | pump is turned on, the pump will not cycle because the | |
| when pump is energized? | compensator is dumping controll pressure to the accumulator tank. | |
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| Check | |
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| Volume control not turned open? | Turm volume control valve | |
No hydraulic oil flow from axial piston |
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pump. | Hydraulic oil level low? | Fill resevouir to proper level. | |
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| Restricted suction screen? | Clean suction screen. | |
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| Main pressure relief valve open | Remove cartridge. Clean and reset. Replace cartridge if | |
| ncessisary. | ||
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| This emergency cycle switch, located in the control box, can be | |
| Proximity switch is not sending a signal? | used to determine which switch is faulty. Determine malfunctioning | |
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| proximity switch and replace. | |
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| Turn on pump switch. Check TB1 terminal #35 and #36 to | |
| Pilot cycle valve malfunction? | determine if current is flowing to valve. Check detents in valve for | |
Drive cylinders will not cycle |
| proper operation. | |
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| Check the proximity switch enclosure. | ||
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| Main cycle valve(manifold) faulty? | Check spool or centering springs. Replace or repair as necessary. | |
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Accumulator pressure drops to zero | Low nitrogen charge in accumulator | ||
on every cycle | bladder? | PSI.) | |
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Accumulator pressure is below 12.1 | Unloading valve setting too low? | Adjust unloading valve until 12.1 mPa (1,750 PSI) is reached. | |
mPa (1750 PSI.) | |||
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Accumulator pressure is not | Cartridge at port | Check solinoid and cartridge. Replace if necessary | |
discharging when switch is turned off | is not working? | ||
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PAGE 68 — MAYCO