Lessen Failure of Hydraulic Systems with Preventive Maintenance

Reducing Hydraulic System Failures Through Contamination Control

The primary defense in minimizing hydraulic system failure is to include contamination measurement and control protocols as a core part of your Preventive Maintenance (PM) program. While it’s not necessary for your shop to be a clean room, it is essential to identify sources of contamination and methods to reduce them.

Types of Contamination:

Built-in Contamination:
Introduced during manufacturing and assembly, this includes debris, weld spatter, casting sand, paint, pipe sealant, or fibers from cleaning cloths.

Normal Contamination:
Particles already present in hydraulic fluid before filtration due to production, packaging, transport, or distribution. Pre-filtering the fluid before adding it to the system is highly recommended.

Ingressed Contamination:
Enters the system through air breathers, rod seals, wiper seals, component seals, or poorly fitted covers. While it can't be entirely avoided, aftermarket solutions exist to reduce it.

Generated Contamination:
Created by wear and tear, including abrasion, cavitation, corrosion, erosion, and fatigue from contact between moving parts.

Catalytic Contamination:
Caused by non-solid contaminants like water, air, or heat reacting with solid particles. For example, water combined with iron or copper can result in a more damaging catalytic reaction.

Measurement and Mitigation:

Contaminants are often invisible to the naked eye. Routine fluid sampling and analysis are crucial for identifying and controlling contamination.

Fluid Analysis:
Identifies contaminants chemically and can point to their sources. Lab testing is typically inexpensive and informative.

Particle Counting:
Provides a measure of contamination severity. Commercial particle counters are available for cost-effective testing.

Prevention:
Frequent fluid changes can help but may reduce productivity. Focusing on high-quality filtration is more efficient. Filters must meet or exceed system specifications for particulate size and flow rate. Always refer to OEM recommendations.

Warning:
Not all filters are equal. They differ in:

The size of particles they are designed to filter.

The flow rate they allow through the filter media.