Cleaning Bio from Pump on Case 1845C

[MikePhua]

The Case 1845C is a compact track loader produced by Case Construction Equipment, a brand with roots extending back to the 19th century and a major global player in earthmoving and material‑handling machinery. Introduced as part of Case’s C‑series lineup, the 1845C blends aggressive breakout force, smooth hydraulic response, and compact undercarriage to serve in grading, trenching, demolition, and site cleanup. Units were manufactured in the tens of thousands worldwide, often powered by turbocharged diesel engines producing around 74–95 hp (55–71 kW) and paired with variable‑displacement axial‑piston pumps delivering hydraulic flow in the neighborhood of 20–25 gpm (75–95 L/min). Over years of operation, a common maintenance issue operators encounter is biofilm or biological contamination inside the hydraulic pump — a condition that, if left untreated, can reduce performance, accelerate wear, and compromise the entire hydraulic system.
Terminology

• Biofilm – A sticky matrix composed of microbes (bacteria, fungi), debris, and degraded fluid that adheres to internal wet surfaces and restricts flow.
  
• Hydraulic Pump – The core component that generates pressurized fluid flow to power loader lift, tilt, and auxiliary circuits.
  
• Axial Piston Pump – A type of variable‑displacement hydraulic pump common in compact track loaders, prized for efficiency and smooth modulation.
  
• Fluid Contamination – The presence of unwanted substances (water, microbes, particulate) in hydraulic fluid, degrading lubricity and pressure.
  
• Filtration Rating – The micron rating that indicates the smallest particle size a filter can effectively remove (e.g., 10 micron, 3 micron).
  

Why Biofilm Forms
Hydraulic systems that operate in humid, warm environments — such as agricultural sites, tropical climates, or indoor dusty warehouses — are susceptible to microbial growth when water and particulate enter the fluid. Biofilm often forms when:

• Water contamination occurs through condensation, poor storage, or inferior seals.
  
• Particles such as dust, rust, or gearbox debris provide nuclei for microbe adhesion.
  
• Old fluid stays in service beyond recommended change intervals, losing detergency and anti‑microbial additives.
  

Biofilms can adhere to pump surfaces, control valves, and hose walls, creating surface roughness that reduces effective flow and promotes further contamination.
Common Symptoms of Biofilm in Hydraulic Pumps
Operators and technicians typically notice several indicators:

• Spongy or delayed hydraulic response — the machine hesitates before lift or tilt functions engage.
  
• Unusual noise from the pump — whining, chattering, or cavitation‑like sounds under load.
  
• Reduced hydraulic power or reduced lift height — especially apparent when moving heavy loads.
  
• Elevated hydraulic oil temperatures during extended cycles due to friction and inefficient flow.
  
• Filter clogging — requiring more frequent filter changes than usual.
  

In field observation, machines with upward of 3,000–5,000 hours without proper fluid maintenance are more likely to exhibit these signs.
Inspection and Diagnosis
To confirm biofilm‑related issues, a technician may:

• Visual fluid check — Hydraulic oil that appears cloudy, milky, or with suspended particles often signals contamination beyond simple wear debris.
  
• Filter inspection — Cutting open a used hydraulic filter can reveal a sticky, gelatinous layer on the media, often indicative of biological material.
  
• Oil analysis — Laboratory tests measuring water content, particle counts, and the presence of microbial metabolites can quantify contamination levels.
  
• Pressure tests — Measuring pump inlet and discharge pressure under load reveals whether internal leaks or surface adhesion are reducing pump efficiency.
  

Steps to Clean Biofilm from a Hydraulic Pump
1. Drain and Clean Reservoir

• Begin by draining all hydraulic fluid from the reservoir.
  
• Remove any sludge or sediment at the bottom of the tank with a lint‑free cloth or vacuum.
  
• If visible deposits line the tank’s interior walls, consider a mild solvent flush followed by a water‑free cleaning solution that is compatible with hydraulic systems.
  

2. Replace Filters and Screens

• Use new hydraulic filters with appropriate micron ratings (usually 3–10 micron) to ensure effective particle removal.
  
• Replace suction screens and any mesh filters in return lines.
  
• Biofilm often hides in filter pleats, so discard old filters rather than attempting to clean them.
  

3. Flush Hydraulic Lines

• Use a hydraulic flushing pump and clean fluid to circulate through all circuits, especially those serving the lift and tilt valves.
  
• Allow the flush fluid to run until clean — usually requiring multiple tank volumes — removing detached biofilm and dislodged debris.
  

4. Inspect and Clean Pump Components

• Remove the hydraulic pump if signs point toward internal contamination.
  
• Disassemble housing and inspect pistons, slippers, and valve assemblies for sticky deposits.
  
• Clean metal parts with appropriate solvent and ensure all orifices and tight clearances are free of sticky residues.
  

5. Refill with Clean, Correct Fluid

• Refill the system with manufacturer‑specified hydraulic fluid, noting viscosity and additive requirements.
  
• Avoid mixing different fluid types; compatibility issues can promote deposits.
  
• Some technicians recommend a fluid with anti‑foam and high oxidation resistance to defend against contamination.
  

6. Monitor Post‑Service Performance

• Run the machine through typical lift, tilt, and travel cycles while monitoring oil temperature and response.
  
• Check filter indicators to ensure that no immediate excessive clogging occurs.
  
• Regularly sample fluid and note any increase in contamination levels.
  

Field Example and Insights
A rental fleet in the southeastern United States experienced progressive sluggishness in several Case 1845C loaders over 18 months of heavy use. Operators reported that lift arms moved slowly under load, and oil temperatures trended 10–15 °F above normal during grading tasks. Inspection revealed filters with oily, slimy material coating the paper. A complete reservoir and pump cleaning followed by fresh fluid and filters restored crisp hydraulic response and cut fluid temperatures back to normal ranges. The key lesson was that recurring symptoms can stem from contamination and not solely mechanical wear.
Another contractor shared that in tropical climates, simply storing equipment outdoors overnight led to humidity and condensation accumulating in hydraulic reservoirs unless the machine was parked with auxiliary pumps running periodically. This micro‑condensation, combined with high ambient temperatures, set the stage for bio film formation that progressively reduced pump efficiency.
Additional Solutions and Preventive Strategies

• Desiccant breathers on the reservoir cap prevent moisture ingress.
  
• Water separators on return lines help retain dry fluid.
  
• Regular fluid sampling every 250–500 operating hours gives early warnings of contamination.
  
• Scheduled filter changes more often than OEM minimums, especially in wet or dusty environments, prevent buildup.
  

Keeping a maintenance log with hydraulic fluid condition trends can reveal progressive issues long before they affect performance. For example, an increasing particle count or rising water percentage often precedes the first visible symptom.
Comparative Notes with Modern Machines
Newer compact track loaders from Case and competitors like Caterpillar and John Deere increasingly incorporate fluid cleanliness monitoring and onboard diagnostics that alert operators to worsening hydraulic conditions before pumps or actuators show performance degradation. While the 1845C predates many modern sensor arrays, its hydraulic system still responds to disciplined maintenance practices.
Conclusion
Biofilm contamination in a hydraulic pump isn’t merely an incidental nuisance; it fundamentally undermines the efficiency and life of critical hydraulic components like axial‑piston pumps, control valves, and actuators. With the Case 1845C and similar loaders, proactive cleaning — involving reservoir flushing, filter replacement, pump disassembly when necessary, and correct fluid selection — returns performance and extends component life. For operators dealing with high humidity, dusty conditions, or irregular service intervals, incorporating desiccant breathers, frequent oil analysis, and aggressive filtration practices pay dividends in uptime and reduced repair costs. Maintaining hydraulic cleanliness remains one of the most important yet overlooked aspects of heavy equipment reliability.