Self-loading mixer (here understood as self-assembled vehicles or self-made vehicles with loading function) oil leakage may involve multiple problems. Here are some common reasons and search directions.

Seal problem
Seals (e. g., oil seal, O-ring) of oil tank, tubing, oil pump, engine and other components may fail due to aging, wear or improper installation, leading to oil leakage.

Check the status of all seals, especially those located on joints or frequently moving parts.

Tubing and connections:
Tubing may leak due to aging, wear, rupture or improper installation.
Check the tubing for cracks, wear, or loosening, and ensure that all connections (e. g., pipe clips, joints) are tight and leak free.

Tank and oil pan:
The tank or oil pan may rupture or perforation due to impact, corrosion, or manufacturing defects.

Check the outside and interior of the tank and oil pan for significant damage or leakage points.

Engine and transmission:
The sealing surfaces of the engine and gearbox may leak due to wear, corrosion or improper assembly.

Check the sealing surface of the engine and gearbox for oil stains, and pay special attention to the oil pan, oil seal and valve chamber cover.

screw bolt and nut:
Fastening bolts and nuts may lead to oil leakage due to loosening.
Check all relevant bolts and nuts to ensure they are tightened at the specified torque.

Overfilling:
If the tank or other fluid container is overfilled, oil leakage may result from fluid spill.
Check that the oil level is within the normal range to avoid overfilling.

Design and Manufacturing Issues:
If the self-loading is self-assembled, there may be design or manufacturing defects, such as unreasonable oil pipe layout, improper oil seal selection, etc.
Review the design and manufacturing process to find and correct potential problems.

service environment:
Poor use environment (such as high temperature, humidity, corrosive substances, etc.) may accelerate oil leakage.

Assess the impact of the use environment on the vehicle and take corresponding protective measures.

More details on self loading mixer truck are on lutonmachinery.com.

In the investigation of oil leakage problems, it is suggested to proceed from easy to difficult, from outside to inside. Check the parts easy to observe and approach, such as tubing, oil tank and oil pan, and then gradually penetrate into complex parts such as engine and gearbox. Also, be careful to keep the working area clean and dry to detect the oil spill point more accurately. If the problem is more complex or difficult to solve, it is recommended to seek professional help.