Troubleshooting Hydraulic and Electrical Issues on the Lollini AL-5000 Scrap Baler

[MikePhua]

The Lollini AL-5000 and Its Industrial Heritage
The Lollini AL-5000 scrap baler was manufactured in Italy during the 1960s, part of a wave of postwar industrial equipment designed to meet growing demand for metal recycling and scrap compaction. Lollini, an Italian engineering firm specializing in balers and shears, produced rugged machines for European and export markets. The AL-5000 was a mid-size baler powered by a Deutz diesel engine and equipped with gear-type hydraulic pumps, making it suitable for yard-scale operations and mobile scrap processing.
Though production numbers are unclear, machines like the AL-5000 were common in European scrapyards and occasionally found their way to North America. Their longevity is owed to simple mechanical construction, but age-related wear and limited documentation pose challenges for modern operators.
Hydraulic Slowness and System Layout
Operators of the AL-5000 have reported sluggish hydraulic response, particularly in the door functions. The machine uses two gear pumps feeding two separate valve banks, each controlling different hydraulic circuits. Despite recent pump and filter replacements, the doors remain slow to actuate, suggesting deeper issues in flow restriction or pressure regulation.
Potential causes include:

• Contaminated suction filters inside the hydraulic tank
  
• Internal leakage in control valves or cylinders
  
• Cold-weather viscosity resistance in older fluid formulations
  
• Pressure loss due to worn pump tolerances or bypassing seals
  

One technician recommended draining the tank and inspecting the suction filters, which are often overlooked during routine service. In older machines, these filters may be clogged with metallic debris or degraded rubber fragments from aging hoses.
Electrical Control and Solenoid Behavior
The AL-5000 uses a 12V electrical system to actuate solenoids that control pilot pressure for each hydraulic function. A common failure mode involves voltage reaching the solenoid but no movement in the associated hydraulic component. In one case, the lower door stopped working despite voltage at the solenoid and free movement of the spool.
This points to a possible failure in the pilot pressure circuit, which relies on a secondary solenoid to open a pilot valve before the main function can engage. If the pilot solenoid fails or a limit switch malfunctions, the main valve remains inactive.
Troubleshooting steps:

• Use a test light to confirm voltage at both solenoids during activation
  
• Inspect wiring for corrosion, loose crimps, or broken insulation
  
• Check continuity through limit switches and relays
  
• Manually test spool movement with the solenoid removed
  
• Verify pilot pressure at the valve block using a gauge
  

A former operator of a Sierra baler—a similar Italian design—reported weekly issues with pilot solenoids and limit switches. Re-crimping and soldering connections often restored function, but intermittent faults persisted due to aging wiring.
Cold Weather Performance and Battery Sensitivity
Italian balers of this era are known to perform poorly in cold conditions until fully warmed. Hydraulic fluid thickens, reducing flow rates and delaying actuation. Additionally, the electrical system is sensitive to battery voltage and alternator output. A weak battery or failing alternator can prevent solenoids from engaging properly, even if voltage appears sufficient at rest.
Recommendations for winter operation:

• Use low-viscosity hydraulic fluid rated for sub-zero temperatures
  
• Install a block heater or hydraulic tank warmer
  
• Maintain battery charge above 12.6V and test under load
  
• Replace alternator if output drops below 13.5V at idle
  

One operator noted that his baler refused to function until the alternator was replaced and the battery upgraded to a higher cold-cranking amp rating.
Mechanical Interference and Dual Function Conflicts
Another quirk of the AL-5000 is its tendency to attempt multiple functions simultaneously, particularly in the lid circuits. When two solenoids are energized at once, the system may prioritize one function, leaving the other inactive. This is often due to shared pilot pressure or valve overlap.
To diagnose:

• Activate one function at a time and observe response
  
• Use a test light to identify which solenoids are live simultaneously
  
• Inspect valve sequencing and pilot routing for interference
  
• Consider installing function lockouts or interlocks to prevent overlap
  

This issue rarely affects the plow or main compression ram, which operate on dedicated circuits. However, lid and door functions may share pilot paths, leading to unpredictable behavior.
Conclusion
The Lollini AL-5000 scrap baler is a testament to mid-century industrial engineering, but its aging hydraulic and electrical systems require careful attention. Sluggish doors, intermittent solenoid response, and cold-weather sensitivity are common challenges. By inspecting suction filters, verifying pilot pressure, and maintaining electrical integrity, operators can restore reliable performance. In machines like the AL-5000, every valve, wire, and fitting tells a story—and solving its quirks is part of keeping that story alive.