Advance Hydraulics

Troubleshooting Power Units

Tech Talk 05/09/00

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Symptom: Dirty Oil

  1. Components are not properly cleaned after servicing.  
  2. Inadequate screening in fill pipe.
  3. Air breather left off; inadequate unit provided.
  4. Tank not properly gasketed.
  5. Pipe lines not properly covered during servicing.
  6. Tank baffles; inadequate settling basin for heavy materials.
  7. Filter elements not frequently replaced.
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Symptom: Fire-Resistant Fluids. 

  1. Incorrect seals cause excessive friction; spool binds.
  2. Paint, varnish & enamel contacting fluids cause sludge deposits. 
  3. Electrolytic action possible with some metals, i.e. zinc, cadmium.
  4. Improper mixtures: heavy sludge formations.
  5. High temperatures adversely affect aqueous-base fluids.  Tanks containing these fluids should be clearly labeled.
  6. Remedy nuisance leaks immediately.
  7. Replacement parts must be compatible with fluid media.

 

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Symptom: Foaming Oil

  1. Return of tank line not below fluid level.  Broken pipe, line left out between bulkhead coupling & tank bottom after cleaning.
  2. Inadequate baffles in reservoir.
  3. Fluid contaminated with foreign matter.
  4. Suction leak to pump aerating oil.  
  5. Lack of anti-foaming additives.

 

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Symptom: Moisture in Oils

  1. Cooling coils not below fluid level.
  2. Cold water lines fastened directly against hot: condensate within tank.
  3. Soluble oil solution splashing into poorly gasketed tanks; fill pipes left open.
  4. Moisture in cans used to replace fluid in tanks.
  5. Extreme temperature differential in certain regions.
  6. Drain not provided in tank's lowest point to remove collected water.
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Symptom: System Overheating

  1. Clogged water shutoff or heat exchanger.
  2. Continuous operation at relief setting: stalling under load, etc.; fluid velocity too high.
  3. Excessive slippage or internal leakage: check stall leakage past pump, motors & cylinders; fluid viscosity may be too low.
  4. Reservoir sized too small, or assembled without sufficient baffling.  
  5. Case drain line from pressure-compensated pump returning oil too close to suction line: repipe case drain line to opposite side of reservoir baffling.
  6. Pipe, tube, hose ID or valving too small, causing high velocity.
  7. Improper air circulation around reservoir. 
  8. System relief valve set too high.  
  9. Power unit operating in direct sunlight or high ambient temperature. 

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Symptom: Foreign Matter

  1. Pipe scale not properly removed. 
  2. Sealing compound (pipe dope teflon tape) inside fittings.
  3. Improperly screened fill pipes & air breathers. 
  4. Burrs inside piping components.  
  5. Tag ends of packing coming loose.
  6. Seal extrusions from pressure higher than compatible with the seal or gasket.
  7. Components not protected during repair; open lines left unprotected.
  8. Wipers or boots not provided on cylinders or rams.
  9. Repair parts & replacement components not properly protected while stored in repair depot. 

 

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The Fluid Power Specialists
1-800-236-1545
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Advance Hydraulics Inc. Advance Hydraulics, Inc.
www.adavancehydraulics.com - Sales@AdvanceHydraulics.com
2525 E. Crawford Avenue St. Francis, Wisconsin 53235
Phone: (414) 481-1545 Fax: (414) 744-1667