ASV RC-100 Slow Right Turn Diagnosing Drive Imbalance and Hydraulic Flow Issues

[MikePhua]

The RC-100 and Its High-Performance Track System
The ASV RC-100 was introduced in the early 2000s as a high-output compact track loader designed for forestry, land clearing, and demanding terrain. Built by ASV Inc., a company known for its patented Posi-Track undercarriage system, the RC-100 featured a 100-horsepower turbocharged Perkins diesel engine, pilot-controlled hydraulics, and a suspended rubber track system that offered exceptional traction and low ground pressure.
Its design emphasized maneuverability, with independent hydraulic drive motors powering each track. This allowed for zero-radius turning and precise control in tight spaces. However, as these machines age, issues with directional responsiveness—especially sluggish turning to one side—can emerge due to hydraulic imbalance, motor wear, or control signal degradation.
Terminology Annotation:

• Posi-Track System: ASV’s proprietary undercarriage featuring suspended bogie wheels and rubber tracks for enhanced traction and ride comfort.
  
• Pilot Control: A low-pressure hydraulic signal system used to actuate main valves and motors.
  
• Drive Motor: A hydraulic motor mounted on each side of the loader, converting fluid pressure into rotational force to move the tracks.
  

Symptoms of Right Turn Sluggishness
Operators may notice:

• Delayed or weak response when turning right
  
• Machine veers slightly even when joystick is centered
  
• Left track appears stronger or more responsive
  
• Audible pitch change in hydraulic system during right turns
  
• Increased fuel consumption due to compensating maneuvers
  

In one forestry operation in Georgia, an RC-100 began drifting left during straight travel. The operator compensated by feathering the right joystick, but over time the imbalance worsened, leading to reduced productivity and increased wear on the left track.
Hydraulic Flow Diagnosis and Motor Testing
The RC-100 uses a dual hydrostatic drive system, with each track powered by a separate hydraulic circuit. When one side underperforms, the issue may lie in:

• Restricted flow to the right drive motor
  
• Internal leakage within the motor
  
• Contaminated pilot valve or clogged orifice
  
• Weak charge pressure feeding the right circuit
  

Diagnostic steps:

• Check hydraulic fluid level and condition—milky or dark fluid indicates contamination.
  
• Inspect pilot pressure at the right joystick output—should match left side within 5%.
  
• Measure case drain flow from the right motor—excessive flow suggests internal leakage.
  
• Swap joystick signal lines to test responsiveness—if the issue reverses, the fault is in the control system.
  

Terminology Annotation:

• Case Drain Flow: Low-pressure fluid exiting a hydraulic motor, used to detect internal leakage.
  
• Charge Pressure: Baseline pressure that feeds the hydrostatic pumps and prevents cavitation.
  
• Orifice Plug: A small restriction in the hydraulic line used to control flow rate and dampen pressure spikes.
  

Recommendations:

• Replace hydraulic filters every 250 hours
  
• Flush system and refill with ISO 46 hydraulic oil
  
• Clean or replace pilot valve cartridges
  
• Inspect motor seals and bearings for wear
  

In one repair case from Alberta, a technician found a partially collapsed hose feeding the right motor. The restriction caused reduced flow and sluggish turning. Replacing the hose restored full responsiveness.
Electrical and Control Signal Considerations
Although the RC-100 is primarily hydraulic, electrical faults can influence joystick behavior. Potential issues include:

• Corroded connectors at the joystick base
  
• Faulty potentiometer affecting signal strength
  
• Grounding issues causing intermittent control loss
  

Solutions:

• Clean all connectors with dielectric cleaner
  
• Test potentiometer resistance and replace if out of spec
  
• Verify battery voltage and alternator output—low voltage can affect solenoid response
  

Adding a diagnostic LED to the pilot control circuit can help monitor signal integrity during operation.
Mechanical Wear and Track Resistance
Sometimes the issue is not hydraulic but mechanical:

• Right track tension may be too tight, increasing resistance
  
• Bogie wheels or idlers may be seized or misaligned
  
• Debris buildup under the track frame can cause drag
  

Preventative measures:

• Inspect and adjust track tension monthly
  
• Grease bogie wheels and idlers every 50 hours
  
• Clean undercarriage daily in muddy or debris-heavy environments
  

In one case from a land-clearing crew in Florida, a seized rear bogie wheel on the right side caused the machine to resist turning. Replacing the wheel and realigning the track resolved the issue without hydraulic intervention.
Preventative Maintenance and Operator Tips
To maintain balanced turning:

• Warm up hydraulics before full-load operation
  
• Avoid abrupt joystick movements that shock the system
  
• Monitor track wear and replace as needed
  
• Log directional responsiveness and service intervals
  

Operators should report early signs of drift or imbalance, as these often precede more serious failures. Installing pressure gauges on both drive circuits can help detect asymmetry before it affects performance.
Conclusion
Sluggish right turns in the ASV RC-100 are typically caused by hydraulic flow imbalance, motor wear, or mechanical resistance. With methodical diagnostics, targeted component replacement, and disciplined maintenance, the issue can be resolved and prevented. The RC-100 remains a powerful and agile track loader—but its precision depends on the harmony of fluid, signal, and structure. In the woods or on the jobsite, every turn counts—and when one side lags, the fix begins with understanding the system beneath the surface.