Bender hydraulic pump common failures and solutions

1. Pump not starting or low pressure

Possible Causes:

• Air in the system: Air can enter the pump or hydraulic lines, causing erratic performance or preventing the pump from starting.
• Low fluid level: If the hydraulic fluid is low, the pump may not get the required suction, resulting in low pressure.
• Faulty pressure relief valve: If the pressure relief valve is stuck or malfunctioning, it may not allow pressure to build up.

Solutions:

• Bleed the system: Ensure that all air is removed from the system. Use a bleed valve or let the pump run under low pressure to expel air.
• Check fluid levels: Verify that the hydraulic fluid is at the proper level and top it up if necessary.
• Inspect the pressure relief valve: Check for blockages or damage to the relief valve and clean or replace it if needed.

2. Pump overheating

Possible Causes:

• Overloaded system: The pump might be under excessive load, causing it to overheat.
• Low fluid viscosity: The wrong type of hydraulic fluid or fluid that’s too thin can lead to overheating.
• Cooling system failure: In systems with a cooling circuit, a malfunction can lead to overheating.

Solutions:

• Reduce the load: Check if the pump is working under excessive load conditions and try to reduce the load.
• Use the correct fluid: Ensure that the hydraulic fluid is the right type and has the proper viscosity for the operating temperature.
• Inspect the cooling system: If the pump has a dedicated cooling system, ensure it's functioning properly and that the fluid isn't too hot.

3. Pump cavitation

Possible Causes:

• Low inlet pressure: If the pump isn’t receiving adequate inlet pressure or flow, cavitation (formation of bubbles) can occur, damaging the pump.
• Dirty or clogged filter: A clogged filter can restrict fluid flow, leading to cavitation.
• Excessive fluid viscosity: Too thick a fluid can also prevent proper flow, causing cavitation.

Solutions:

• Check inlet pressure: Ensure that the pump is receiving the correct inlet pressure and that the intake line is clear of blockages.
• Clean or replace filters: Inspect and clean the filters regularly to ensure free fluid flow.
• Check fluid viscosity: Verify that the fluid’s viscosity is within the manufacturer’s recommended range.

4. Excessive noise or vibration

Possible Causes:

• Incorrect pump alignment: Misalignment of the pump or motor can cause vibration and noise.
• Worn components: Over time, bearings, seals, or gears inside the pump can wear down, leading to noisy operation.
• Contaminated fluid: Dirt or metal particles in the hydraulic fluid can damage internal components, causing noise.

Solutions:

• Check alignment: Ensure that the pump and motor are properly aligned and that the mounting hardware is tight.
• Inspect internal components: If noise persists, inspect the pump for worn-out bearings, gears, or other internal parts and replace them as needed.
• Change the fluid: If the fluid is contaminated, replace it and ensure the filtration system is working properly.

5. Leaks

Possible Causes:

• Worn seals or O-rings: Over time, seals and O-rings can deteriorate, causing leaks.
• Loose fittings: Hydraulic fittings may loosen over time, leading to fluid leaks.
• Cracked pump housing: A crack in the pump body or housing can cause fluid leaks.

Solutions:

• Replace seals/O-rings: Inspect all seals and O-rings and replace them if they are worn or damaged.
• Tighten fittings: Ensure all hydraulic fittings are tight and secure. Use thread sealant where necessary.
• Inspect for cracks: If the pump housing is cracked, it may need to be replaced or welded (depending on the severity of the crack).

6. Pump producing insufficient flow

Possible Causes:

• Internal wear: Wear of the internal components, such as the gears or pistons, can reduce the pump’s ability to generate the required flow.
• Blocked suction line: A blockage in the suction line can reduce flow.
• Contaminated fluid: Contaminants in the fluid can impair pump performance.

Solutions:

• Inspect internal parts: Check the pump’s internal components for wear and replace parts as necessary.
• Clear suction line: Ensure that the suction line is free from blockages and that the filter is clean.
• Change fluid: Replace contaminated hydraulic fluid to restore proper pump performance.