Why Do Oil Leaks Occur in Hydraulic Systems? Causes and Prevention

A few drops of hydraulic oil pooling on a workshop floor look like a minor cosmetic issue. In reality, it's often the first sign that pressure is escaping somewhere in the system - and that efficiency is dropping with it.

1. Where the Leak Comes From

1.1. Static Leaks

Usually caused by hardened seals, incorrect torque, or dirt buildup on the surface; easy to spot because the source stays fixed.

1.2. Dynamic Leaks

Occurs between a moving surface (piston rod or shaft) and its seal. Every motion cycle wears the seal surface microscopically, so a dynamic leak is a problem that worsens gradually.

2. Typical Causes

• Wrong Seal Choice: an elastomer incompatible with the oil type swells or hardens within months
• Material Aging: standard NBR seals start losing flexibility after 8-10 years even without visible failure
• Hose Loosening: fitting connections loosen over time in vibrating environments, and torque deviation starts micro-leaks

"Finding and fixing the source of a leak, rather than just wiping it away, saves both oil cost and the downtime a hydraulic failure would cause."

— BRS PROSES Engineering Team

3. Prevention and BRS Proses Support

Keeping torque values consistent with manufacturer tables and choosing seals matched to oil type prevents most leaks before they start:

• On-site leak source diagnosis
• Seal material recommendation matched to oil type
• Contamination control via ISO 4406 particle counting
• Periodic torque and seal-life scheduling