There were 8 large shovel maintenance trucks of Shenzhen Dachanwan arrived to port, 4 of them were found skew in hook up and down in the operation. "high reliable products, life-long warranty" is the policy of General Corporation. General Manager Li was informed that situation, the he attached great importance to organization of technical design and after-sales service personnel to find out the reason and come up with solutions and called for product warranty to 20 years. The company sent Liu Yimei To to Shenzhen port on July 1st and organized three comrades of Shenzhen Office to reform the issue. They overcame all the difficulties to modify the design of the hook on the brakes for enhanced handling, nearly half a month another 8 reformed. After user tests, the traffic has been operating normally and approved. For me and the company's rapid after-sales service and construction work, the users gave good evaluation.