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Global solutions in hydraulic. Since 1965

Oil management

Up to 90% of all failures in a hydraulic system can be attributed to contaminated oil which often results in downtime and associated costs.

Stern’s proposed oil management system can anticipate such failures and downtime and also prolong the life of the unit, consequently reducing the costs associated with maintenance.

BASIC ANALYSIS Performed in situ on the client’s premises

Stern provides a service to measure the following parameters:

  • The level of solid contaminant particles according to ISO 4406, SAE AS4059 and NAS 1638-1
  • Degree of water saturation in % and fluid temperature for hydraulic oils up to ISO VG 68 (50 mm2/s) viscosity

FULL ANALYSIS Performed in laboratory

These processes require a sample for analysis in the laboratory. The data obtained are more comprehensive and may include:

  • General specifications: Amount of water measured in ppm, acidity index indicative of the degree of aging, viscosity
  • Presence of degraded additives
  • Contaminating metals and wear

Type of contaminant:

Type of contamination

Gaseous: Air

Liquid: Water


  • Extremely hard particles: Oxide | Affects: Extremely abrasive
  • Hard particles: Iron, steel, brass, bronze, aluminium | Affects: Highly abrasive
  • Soft particles: Fibres, plastic, paint, gaskets | Affects: Slightly harmful