The correct hydraulic oil level for small four-wheel tractors is between the "MAX" (upper) and "MIN" (lower) scale lines marked on the oil tank or oil gauge, and it is recommended to keep it close to the "MAX" scale (but not exceeding it) under normal conditions.
1. Core Judgment Standards
1.1 Standard Position
When the tractor is parked on flat and horizontal ground (critical for accurate measurement), the engine is shut down, and the hydraulic control valve is in the neutral position (to allow oil in pipelines and cylinders to flow back to the tank), the oil surface must be within the range of the two scale lines.
Ideal level: Close to the "MAX" scale (about 80%-90% of the tank capacity). This ensures sufficient oil supply during high-load operations (e.g., lifting heavy attachments) and avoids oil shortage caused by oil flow.
1.2 Prohibited Positions
Do not let the oil level drop below the "MIN" scale: Insufficient oil will cause poor lubrication, pump cavitation (abnormal noise), and overheating of the system.
Do not exceed the "MAX" scale: Excessive oil will cause overflow during system operation (especially when the oil expands due to heating), and may increase system pressure, leading to oil leakage.
2. Correct Checking Steps
Park the tractor on flat ground, shut down the engine, and wait for 5-10 minutes (ensure oil in the hydraulic cylinder and pipeline flows back to the tank).
Return the hydraulic control lever (e.g., attachment lift lever) to the neutral position to release residual pressure.
Clean the surface of the oil tank cap with a rag, then open the cap.
Observe the built-in scale on the tank inner wall or the oil gauge rod attached to the cap:
For built-in scales: Directly check the oil surface alignment with MAX/MIN.
For oil gauge rods: Insert the rod fully into the tank, pull it out and wipe it clean, reinsert and pull out again-the oil stain position should be between the two scale lines on the rod.
After checking, close the oil tank cap tightly to prevent dust from entering.
3. Key Notes
Check the oil level before each startup (daily routine inspection) to avoid problems during operation.
If the oil level drops rapidly (e.g., from MAX to near MIN within tens of working hours), do not simply add oil-first check for oil leakage (pipe joints, cylinder seals) or internal component failure (e.g., cylinder internal leakage).
When adding new oil, add it slowly with a funnel (with a filter screen) to avoid generating foam, which may cause misjudgment of the oil level.
