Hydraulic System Air Removal Procedures for Roll Forming Machines | Guide

Hydraulic System Air Removal Procedures for Roll Forming Machines

1. Introduction

Hydraulic systems are widely used in roll forming machines to power essential production components such as hydraulic cutting systems, punching units, flying shear mechanisms, decoilers, coil handling equipment, and automated production devices. These systems rely on pressurized hydraulic oil to transmit power and operate hydraulic cylinders and valves.

For a hydraulic system to function properly, the hydraulic oil must remain free from air contamination. Air trapped inside the hydraulic system can significantly affect system performance and may lead to serious mechanical problems.

Air may enter the hydraulic system through several pathways, including:

• Improper hydraulic oil filling procedures
• Loose hydraulic fittings
• Leaking suction lines
• Maintenance work on hydraulic components
• Low hydraulic oil levels

When air becomes trapped in the hydraulic system, it may cause several operational issues, including:

• Erratic hydraulic cylinder movement
• Spongy or delayed system response
• Increased system noise
• Reduced hydraulic pressure
• Hydraulic pump cavitation

Air bubbles inside the hydraulic oil compress under pressure, which reduces the system's ability to transmit force efficiently. This can lead to inconsistent machine operation and reduced hydraulic performance.

In severe cases, air contamination can cause hydraulic pump damage due to cavitation. Cavitation occurs when air bubbles collapse under pressure, creating shock waves that can damage pump components.

Proper air removal procedures are essential after hydraulic maintenance, oil replacement, or component replacement.

Factories that follow proper hydraulic air removal procedures often experience:

• Improved hydraulic system stability
• Reduced pump noise and vibration
• More consistent cylinder operation
• Extended hydraulic component lifespan
• Reduced machine downtime

This guide explains how air enters hydraulic systems and outlines the procedures technicians should follow to remove trapped air from hydraulic systems used in roll forming machines.

These procedures apply to many types of roll forming machines including:

• Roofing panel roll forming machines
• Structural deck roll forming machines
• Purlin roll forming machines
• Metal stud roll forming machines
• Trim and flashing roll forming machines

Although hydraulic system configurations may vary between machines, the air removal principles remain consistent across most roll forming equipment.

2. Components Involved

Hydraulic air removal involves several components within the hydraulic system.

Hydraulic Reservoir

The reservoir stores hydraulic oil and allows air bubbles to separate naturally from the oil.

Proper reservoir design helps prevent air circulation.

Hydraulic Pump

The hydraulic pump circulates oil throughout the system.

Air entering the pump may cause cavitation and noise.

Hydraulic Cylinders

Hydraulic cylinders convert fluid pressure into mechanical movement.

Air trapped in cylinders may cause jerky or inconsistent movement.

Hydraulic Valves

Hydraulic valves control oil flow and pressure.

Air bubbles may interfere with valve operation.

Hydraulic Lines and Hoses

Hydraulic hoses and lines transport oil between system components.

Air pockets may become trapped in these lines.

3. Causes of Wear or Failure

Air contamination in hydraulic systems may occur due to several factors.

Improper Oil Filling

Adding oil too quickly may introduce air bubbles into the system.

Loose Suction Lines

Loose suction fittings may allow air to enter the pump inlet.

Low Hydraulic Oil Levels

Low oil levels may allow air to enter the pump suction line.

Seal Damage

Damaged seals may allow air to enter the hydraulic system.

Maintenance Work

Air may enter the system during component replacement or repairs.

4. Inspection Procedure

Inspection helps determine whether air contamination is present.

Step 1 – Pump Noise Inspection

Air contamination often causes hydraulic pumps to produce unusual noise.

Step 2 – Cylinder Movement Inspection

Technicians should observe cylinder movement for jerky or delayed motion.

Step 3 – Oil Inspection

Hydraulic oil may appear foamy if air is present.

Step 4 – Pressure Inspection

Hydraulic pressure fluctuations may indicate air contamination.

Step 5 – Suction Line Inspection

Suction lines should be inspected for leaks or loose fittings.

5. Maintenance Procedure

Proper maintenance procedures help remove air from the hydraulic system.

Fill Hydraulic Reservoir Slowly

Hydraulic oil should be added slowly to reduce air introduction.

Operate the System at Low Pressure

Running the system at low pressure helps air bubbles move toward the reservoir.

Cycle Hydraulic Cylinders

Repeatedly cycling cylinders helps push trapped air out of the system.

Bleed Hydraulic Components

Some systems include bleed screws that allow trapped air to be released.

Tighten Suction Line Fittings

Loose fittings should be tightened to prevent air entry.

6. Preventative Maintenance Tips

Preventative maintenance helps reduce air contamination.

Maintain Proper Oil Levels

Correct oil levels prevent air from entering the suction line.

Inspect Suction Lines Regularly

Suction leaks should be repaired immediately.

Fill Oil Carefully

Avoid introducing air during oil filling.

Inspect Seals and Fittings

Damaged seals should be replaced promptly.

7. Common Mistakes

Maintenance mistakes may cause hydraulic air problems.

Running the Pump with Low Oil Levels

Low oil levels may introduce air into the system.

Ignoring Foamy Oil

Foamy oil may indicate air contamination.

Failing to Bleed the System

Air trapped in the system may affect machine operation.

Overlooking Suction Line Leaks

Small suction leaks may allow air to enter the system.

8. FAQ Section

What causes air in hydraulic systems?

Air may enter through loose fittings, low oil levels, or improper filling procedures.

What are signs of air contamination in hydraulic systems?

Common signs include pump noise, foamy oil, and erratic cylinder movement.

Can air damage hydraulic pumps?

Yes. Air bubbles may cause cavitation that damages pump components.

How is air removed from hydraulic systems?

Air is removed by cycling the system and bleeding trapped air from components.

Can air contamination affect machine performance?

Yes. Air reduces hydraulic system efficiency and stability.

9. Machine Matcher Support

Removing air from hydraulic systems is essential for maintaining reliable roll forming machine operation. Proper air removal procedures help ensure stable hydraulic pressure and prevent pump damage.

Machine Matcher provides technical support services for roll forming equipment worldwide including:

• Machine inspections
• Hydraulic system diagnostics
• Maintenance program development
• Remote troubleshooting
• Spare parts sourcing

Machine Matcher works with manufacturers worldwide to maintain reliable roll forming production and extend machine lifespan.