To check the hydraulic oil level on an excavator, first turn off the machine and let the oil settle. Use the dipstick or sight glass to measure the level, ensuring it is between the minimum and maximum marks. Top up with manufacturer-recommended hydraulic oil if needed, and always check on level ground while wearing gloves and eye protection for safety.
Hydraulic oil is the lifeblood of an excavator, ensuring smooth operation of the boom, arm, bucket, and other components. Knowing how to check the hydraulic oil level on an excavator is critical for anyone operating or maintaining heavy machinery in the UK. Incorrect oil levels can lead to poor performance, increased wear, and even costly mechanical failures. This detailed guide explains step by step how to check hydraulic oil safely and effectively, along with tips on maintenance, safety, and best practices.
Why Checking Hydraulic Oil Is Important
Hydraulic oil performs multiple essential functions in an excavator. It:
- Transfers power to hydraulic components
- Lubricates moving parts to reduce friction and wear
- Dissipates heat generated during operation
- Protects metal surfaces from corrosion
- Carries contaminants to filters for system cleanliness
Running an excavator with too little or too much hydraulic oil can cause serious problems, including:
- Reduced lifting and digging efficiency
- Increased hydraulic system stress
- Overheating of components
- Potential leaks and equipment damage
Regularly checking oil levels helps avoid downtime and costly repairs, and ensures your excavator operates at peak performance.
When to Check Hydraulic Oil
Hydraulic oil should be checked:
- Before starting the excavator each day
- After extended use or heavy workloads
- Following a hydraulic oil change or system maintenance
- If you notice unusual noises, slow response, or jerky movements
Checking at consistent intervals prevents unexpected hydraulic failures and extends the machine’s life.
Tools Needed to Check Hydraulic Oil Level
Before starting, gather the tools and materials you will need:
- Clean cloth or rag
- Gloves for safety
- Owner’s manual for your specific excavator model
- Measuring tools (if the excavator uses a sight gauge or dipstick system)
Always use clean tools to prevent contamination, as dirt or debris can compromise the hydraulic system.
Locating the Hydraulic Oil Reservoir
The first step is locating the hydraulic oil reservoir, which is typically marked and easily accessible. Depending on the excavator make and model, the reservoir may be:
- Inside a side compartment
- At the rear of the machine
- Integrated with the main engine housing
Refer to the operator’s manual for the exact location, as incorrect access can be dangerous or cause oil spills.
Using a Dipstick to Check Hydraulic Oil Level
Many excavators use a dipstick similar to engine oil checks. Here’s how to use it:
- Turn off the excavator and let it sit for a few minutes to allow the oil to settle.
- Open the reservoir cap carefully to avoid splashes.
- Remove the dipstick and wipe it clean with a rag.
- Reinsert the dipstick fully and remove it again to check the oil level.
- Compare the oil mark with the minimum and maximum indicators on the dipstick.
- Add hydraulic oil if the level is below the recommended mark, but never overfill, as this can cause pressure problems.
Always use the type and grade of hydraulic oil recommended by the manufacturer, often listed in the manual or on the dipstick itself.
Using a Sight Glass or Level Indicator
Some modern excavators have a sight glass or level indicator on the side of the hydraulic reservoir. This provides a quick and visual method to check oil levels:
- Ensure the excavator is on level ground for an accurate reading
- Clean the sight glass to remove dirt and debris
- Observe the oil level between the minimum and maximum marks
- Top up only if the oil is below the recommended range
Sight glasses are convenient but should be periodically cross-checked with a dipstick for accuracy.
Safety Precautions While Checking Hydraulic Oil
Working with hydraulic systems can be dangerous if proper precautions are not taken:
- Always turn off the excavator before checking oil
- Wear gloves and eye protection
- Avoid hot surfaces, as hydraulic oil can become extremely hot after use
- Never remove caps under pressure to prevent oil sprays
- Clean spills immediately to avoid slips and environmental damage
Following safety guidelines protects both the operator and the machine.
Signs Your Hydraulic Oil Needs Attention
Regular checks are important, but you should also watch for warning signs that hydraulic oil may be degraded or contaminated:
- Dark or discoloured oil
- Foaming or frothy oil
- Strange noises in the hydraulic system
- Reduced responsiveness or slow movements
- Frequent filter blockages
If any of these signs appear, consult a professional technician and consider changing the oil.
How to Top Up Hydraulic Oil
If the oil is low, follow these steps:
- Use a clean funnel to prevent contamination
- Pour manufacturer-approved hydraulic oil slowly
- Check the level frequently while filling
- Replace the cap securely
- Operate the machine briefly and recheck the level to ensure accuracy
Do not overfill, as hydraulic systems rely on oil expansion and proper reservoir capacity to operate safely.
Importance of Using the Right Hydraulic Oil
Excavators rely on high-performance hydraulic oil to maintain efficiency. Using the wrong type can cause:
- Increased wear on components
- Poor temperature stability
- Foaming and cavitation
- Potential system failure
Always check manufacturer recommendations, taking into account viscosity, additives, and environmental conditions, especially in the UK, where temperature variations can be significant.
Regular Maintenance Tips for Hydraulic Oil
Proper maintenance ensures long-term system reliability:
- Check oil level daily and top up as needed
- Replace hydraulic oil according to the maintenance schedule
- Inspect hoses and seals for leaks or damage
- Change filters regularly to prevent contamination
- Keep the reservoir and surrounding area clean
Preventive maintenance reduces downtime and protects expensive excavator components.
Environmental Considerations
Hydraulic oil spills can cause environmental harm. To minimise impact:
- Use drip trays during topping up or maintenance
- Dispose of used hydraulic oil responsibly through approved recycling facilities
- Prevent leaks by regularly inspecting hoses and fittings
- Avoid draining oil onto soil or watercourses
UK regulations require the responsible handling of hydraulic fluids to protect the environment.
Troubleshooting Common Hydraulic Oil Issues
Understanding common issues can help operators respond quickly:
- Low oil level: causes sluggish performance, overheating, and noise
- Foamy oil: indicates air in the system, possibly from leaks or overfilling
- Dirty or contaminated oil: leads to accelerated wear and blocked filters
- Unusual noises: may suggest cavitation or pump issues
Early detection and action prevent costly repairs and downtime.
Benefits of Regular Oil Checks
Consistently monitoring hydraulic oil levels offers many advantages:
- Increased machine reliability
- Extended component lifespan
- Reduced risk of breakdowns
- Lower repair costs
- Improved operational efficiency
Even a few minutes spent checking oil daily can save significant time and expense over the lifetime of an excavator.
When to Seek Professional Help
Some situations require a trained technician:
- Persistent hydraulic oil leaks
- Contaminated or degraded oil beyond normal maintenance
- Pump or cylinder issues causing abnormal pressure
- Replacing large quantities of oil or flushing the system
Professional support ensures safe, effective solutions that preserve your equipment investment.
Final Thoughts
Knowing how to check the hydraulic oil level on an excavator is essential for safe, efficient, and reliable operation. By using a dipstick or sight glass, following safety procedures, and adhering to manufacturer recommendations, you can maintain optimal oil levels, prevent mechanical failures, and extend the life of your machine. Consistent checks, proper topping up, and preventative maintenance protect your investment and help keep your excavator performing at its best. 123 Oil provide guidance and high-quality hydraulic oils to keep your machinery running smoothly across the UK.
Regular monitoring of hydraulic oil is not just a maintenance task – it is a crucial part of responsible and professional excavator operation.
Frequently Asked Questions
You can check hydraulic oil using the dipstick or sight glass on the reservoir. Always check on level ground with the excavator turned off and allow oil to settle.
Hydraulic oil should be checked daily before use, after heavy workloads, and following maintenance or oil changes to ensure proper system performance.
Low hydraulic oil can cause slow or jerky movements, overheating, increased wear, and potential hydraulic system damage, reducing overall machine efficiency.
No. You must use the manufacturer-recommended hydraulic oil with the correct viscosity and additives to ensure safe operation and avoid component damage.
Turn off the machine, use a clean funnel, add the recommended oil slowly, check levels frequently, and never overfill. Always wear gloves and eye protection.
