Imagine a hardworking sanitation vehicle traversing city streets day after day, silently maintaining urban cleanliness. While components like diesel particulate filters, engine oil, coolant, tires, brake pads, and batteries receive regular attention, the hydraulic system—the unsung hero—often gets neglected. Does this reveal a critical blind spot in municipal fleet maintenance?

Functioning like circulatory vessels, hydraulic systems power essential components such as trash compactors and front-loader arms while enduring tremendous operational stress. Despite their importance, these systems frequently escape notice due to longer maintenance intervals compared to other chassis components. While manufacturers establish varying service schedules based on operational models, typical maintenance cycles prioritize hydraulic fluid at the top:

• Engine oil — 250 hours
• Automatic transmission — 500 hours
• Standard transmission — 1,000 hours
• Rear differential — 600 hours
• Power steering — 1,000 hours
• Coolant — 1,000 hours
• Hydraulic fluid — 1,000 hours

Darry Stuart, president of DWS Fleet Management Services, emphasizes: "Excessive focus on truck preventive maintenance often overshadows the body and hydraulic system. Though hydraulic fluid changes occur less frequently than engine oil, its cleanliness proves more critical—hydraulic valves, seals, and pumps operate with near-zero tolerances."

Stuart notes that hydraulic cylinders operating compactors and loader arms endure heavy loads while being exposed to dirt and contaminants that can infiltrate the system.

Hydraulic hose wear demands vigilant inspection. "I've witnessed hose failures from branches snagging lines, friction against structures during sharp turns, pump damage from impacts, or frozen container lifting attempts," explains Darryn Wallace, AMSOIL Inc. senior technical services expert. Standard 40-50 gallon hydraulic reservoirs can drain completely within two minutes if lines rupture.

Stuart stresses precision in hose replacement: "Length discrepancies of mere inches can reduce service life by years."

Electronic components also require attention. "Hydraulic operations involve numerous electrical elements—joystick controllers, relays, switches, wiring. Many perceived hydraulic failures actually stem from electrical issues," Stuart adds.

Wallace clarifies: "Most hydraulic fluids adequately manage heat generation when meeting viscosity requirements for operating temperatures." While petroleum-based fluids may need seasonal changes, synthetic alternatives with higher viscosity indexes eliminate this requirement.

Oil analysis plays a crucial role in long-term maintenance. "For hydraulic systems, analysis primarily detects contaminants like water and dirt rather than wear metals," Wallace notes. Particle counting remains the most common diagnostic method, though advanced analyses can predict pump lifespan by identifying wear particle characteristics.

Synthetic fluids offer efficiency advantages: "Premium synthetic hydraulic oils meeting top efficiency specifications can reduce energy costs by 6-15% while potentially increasing productivity," Wallace states.

Tom Price, Heil Environmental product engineering manager, advocates daily inspections and quality lubricants: "Monitoring hydraulic pressure reveals filter blockages. Bypassing clogged filters allows contaminants into the system."

Beacon Funding Corp. underscores that maintenance costs pale against operational losses: "Calculate your truck's daily revenue generation—that's what downtime costs you." The company illustrates how a $40 seal replacement left unattended can escalate into $600 pump replacements with compounded oil losses.

Stuart concludes: "Quality lubricants and oils represent the most cost-effective maintenance. Budget constraints tempt operators toward cheaper products, but increased failures and downtime ultimately cost far more than any initial savings."

• Neglecting loose connection inspections
• Ignoring leaking cylinder seals
• Using incorrect viscosity fluids
• Failing to clean seal areas
• Improper tank vent maintenance
• Incorrect fluid levels
• Improper washing techniques introducing moisture
• Using substandard filters
• Inadequate pin and bushing lubrication

Waste Management currently tests four Peterbilt Model 320 hybrid collection trucks in Fort Worth, Texas, featuring Eaton's Hydraulic Launch Assist (HLA) system. Though separate from compactor hydraulics, both systems share components for maintenance efficiency.

The 1,000-pound HLA system captures braking energy to assist acceleration between stops. Lab tests indicate 25-33% fuel savings, reduced engine wear, and 50% longer brake life—benefits now undergoing real-world validation.

WM Fleet and Logistics VP Eric Woods remarks: "While early-stage, these investments may ultimately reduce greenhouse emissions and benefit heavy equipment manufacturers and operators."