10 Tips for Working Safely with Hydraulic Pumps

Hydraulic tools are powered by hydraulic pumps. To ensure safe and reliable operation, it's essential to use and maintain the pump correctly. Follow these 10 practical safety tips.

1. Check the hydraulic oil level before use

Always check the oil level with the pump placed on a level surface.

• Fill the reservoir only up to the indicated level mark.

• Replace the hydraulic oil regularly, at least once a year.

• Use hydraulic oil with a viscosity grade of ISO VG 36.

• If the pump is operated at temperatures below -10°C (14°F), use ISO VG 15 hydraulic oil instead.

2. Check the fuel level before use

For engine-driven pumps, always check the fuel level with the pump on a level surface.

• Ensure there is sufficient fuel to prevent the engine from stopping unexpectedly during operation.

• Never fill the fuel tank above the maximum level to allow for proper ventilation.

• Never refuel while the engine is running.

• Use clean fuel only and prevent dirt, dust or water from entering the fuel tank to avoid engine damage.

3. Choose the right hydraulic pump

Not every hydraulic pump is suitable for every hydraulic tool. The required oil volume and valve configuration determine which pump is appropriate.

Select a pump with sufficient oil capacity for the tools being operated.

Minimum effective reservoir capacity = (Cylinder 1 oil volume + Cylinder 2 oil volume + ...) × 1.2 (20% safety margin)

Then choose the appropriate pump type:

• Hand and foot pumps: Suitable for smaller hydraulic tools, such as cylinders. For double-acting tools with hydraulic return, always use a double-acting valve.

• Motor-driven pumps: Fit a single-acting valve for single-acting tools and a double-acting valve for double-acting tools.

4. Always connect both couplings when using double-acting tools

Double-acting (hydraulic return) tools require two hydraulic connections: one for the incoming oil flow and one for the return flow.

During extension, hydraulic oil enters the lower chamber through the lower coupling, pushing the piston outward. Oil from the upper chamber simultaneously returns to the pump through the upper coupling. During retraction, this process is reversed.

If the pump has only one coupling, it is not suitable for operating double-acting hydraulic tools.

5. Tighten hydraulic couplings by hand only

Always tighten couplings by hand until no thread is visible between the two coupling halves.

• Never use pliers, wrenches or other tools to tighten hydraulic couplings.

• If a coupling cannot be fully tightened by hand, the thread may be damaged or residual pressure may still be present in the hydraulic system.

6. Prevent damage to the hydraulic system

Protect all hydraulic components against damage during use.

• Shield hoses and components from sparks generated during welding or grinding to prevent leaks.

• Always lift hydraulic pumps using the designated handle or lifting eyes.

• Never lift the pump by the hose or coupling.

• Prevent hoses from kinking, twisting or becoming crushed, as this can lead to leaks and premature failure.

7. Place the pump on a stable surface

Always operate the hydraulic pump on a firm, level and stable surface to prevent it from slipping or tipping over during use.

8. Release system pressure before disconnecting hoses or tools

Before disconnecting any hydraulic hose or tool, always release the pressure from the hydraulic system.

This allows the couplings to be disconnected by hand and prevents residual pressure from remaining in the system, which could cause problems during the next use.

9. Keep the hydraulic system clean

Contamination shortens the life of hydraulic equipment.

• Keep dirt away from hydraulic couplings.

• During operation, screw the dust caps together and clean them after use.

• Painted, plastic and rubber components are not resistant to corrosive chemicals. If they come into contact with acids or other aggressive liquids, rinse them thoroughly with clean water (excluding electrical components).

• Dry the pump after use in wet conditions.

• Apply a thin layer of protective oil to unpainted or black-finished metal parts to prevent corrosion.

• Store the pump horizontally in a dry, well-ventilated area.

10. Have the pump serviced and inspected annually

All hydraulic pumps require periodic maintenance and annual inspection by a qualified professional to ensure safe and reliable operation throughout their service life.

Always verify that the technician has the appropriate certifications or training. At a minimum, they should have completed a basic hydraulics training course. If they are not properly qualified, they should not perform maintenance or inspections on your hydraulic pumps.

Download our whitepaper

Hydraulic high-pressure tools deliver tremendous force. But with that power comes responsibility. What should you look out for? What are the risks? How can you prevent accidents and avoid unnecessary downtime in your daily operations?

Holmatro and Mennens share their expertise and practical advice to help you work safely and efficiently with hydraulic equipment.

This whitepaper is only available in Dutch!