The operating principle of hydraulic system on loaders is briefly described and the criteria of sinking amount is presented. It is suggested that boom sinking is caused by internal and external leakage of hydraulic components like cylinders and valves. Appropriate troubleshooting and remedies are given. The operating principle of hydraulic system on loaders is briefly described and the criteria of sinking amount is presented. It is suggested that boom sinking is caused by internal and external leakage of hydraulic components like cylinders and valves. Appropriate troubleshooting and remedies are given.