Excavator Maintenance: A Senior Engineer's Guide to 5 Key Daily Practices

As infrastructure and construction projects continue to heat up, the excavator—often called the "core asset" on any job site—directly determines project profitability through its uptime and lifespan. Unfortunately, many owners wait until the machine breaks down to think about repairs, resulting in high costs and serious project delays.

Recently, a group of frontline service engineers issued a collective reminder: The real way to save money on an excavator is not through repair, but through preventive maintenance. Below are five key daily maintenance practices, applicable to all major brands including Caterpillar, Komatsu, Hitachi, Sany, and XCMG.

1. Change the "Three Filters" and Engine Oil Regularly (The Most Critical)

The engine is the "heart" of the excavator, while oil and filters are the "blood" and "kidneys."

• The problem: Many owners use cheap, low-quality filters or go too long between oil changes, leading to premature engine wear or even seized cylinders.

• Recommendation: Strictly follow the intervals in your operation and maintenance manual (typically every 250–500 hours) to replace the fuel filter, oil filter, air filter, and high-quality engine oil. Never use counterfeit or low-quality aftermarket filters—they lack proper filtration and can cause injector clogging or turbocharger damage.

2. Grease Properly to Prevent Abnormal Wear

The excavator's working attachments (boom, arm, bucket) and swing bearing contain dozens of pins and bushings. Without proper lubrication, these will quickly experience metal-on-metal wear, leading to excessive play and inaccurate operation.

• Golden rule: Add grease every 8–10 working hours (or every shift) until fresh grease is forced out of the gaps. Increase frequency during rainy seasons or after working in water.

3. Pay Attention to the Hydraulic System – Control Temperature and Cleanliness

The hydraulic system is the "muscle" of the excavator, responsible for transmitting power. Overheating or contamination of the hydraulic oil is a leading cause of main pump and control valve failure.

• Daily checks: Verify that the hydraulic oil level is between the marks on the dipstick. Check that the hydraulic oil cooler is free of debris.

• Change intervals: Replace the hydraulic oil, return filter, and pilot filter around every 2,000 hours for the first change, then adjust based on operating conditions. Never mix different brands or grades of hydraulic oil.

4. Undercarriage and Swing System – Easily Overlooked Cost Traps

Replacing the track system or swing bearing can easily cost tens of thousands of dollars.

• Track maintenance: Regularly check track tension (too loose causes derailment, too tight accelerates wear). Remove mud and rocks from between the tracks to prevent premature damage to the drive sprocket and idler.

• Swing bearing: Regularly check that the swing ring gear bolts are tight. Add extreme-pressure lithium grease through the dedicated port at the recommended intervals.

5. Keep a "Maintenance Log" – Boost Resale Value

Smart owners keep a maintenance log for each excavator, recording every filter change, oil change, and hydraulic fluid change along with the hour meter reading.

• Long-term value: When it's time to sell the equipment, a complete maintenance record proves the machine has been well cared for. Resale prices can be 15–25% higher compared to machines with no service history.

Expert's Final Word

"In this industry, downtime is the biggest cost," says Wang, an experienced service engineer. "A small investment of a few hundred dollars in filters and oil can prevent an engine overhaul that costs tens of thousands. For budget-conscious users, rather than taking a risk on a used engine of unknown origin, put that energy into following a strict maintenance schedule—it's the highest-return investment you can make."