Chery S18D Service Manual
(2) Clean the vehicle doors. Use fresh water or detergent to clean the dirt and greasy spots on the
door panels, and let them thoroughly dry for tests.
(3) Maintenance appraisal. Appraise the scope and degree of damage to the door panels by testing
and decide the maintenance methods.
(4) Clear the old paint. Before cleaning or maintenance, get rid of the old paint according to the actual
situation, especially when there exists obvious rust, cracks or dents; The paint can be got rid of in
manual, heating, mechanic or chemical method(s).
Painted surface Welding torch
Scraper
Fig. 3
(5) Tests after the removal, including the measurements of the geometric dimensions between various
plate work pieces, tests of specific damage spots of various plate work pieces, recognition of
damage types, analyses of damage causes and choices of maintenance schemes.
3. Main Contents of Door Panel Maintenance
Generally speaking, the causes of door panel damages are related to the following 4 aspects: structure
design defects, manufacturing defects, chemical erosion, and physical damage. And the most common
damage causes can be classified as the following types:
1.
Abrasion: The surfaces of plate work pieces may contact each other and relative movements will
take place and cause surface friction, which will lead to abrasion. For example, the long time
friction between the hinge hole and the shaft of the vehicle door hinge will increase their tolerance
clearance and cause to vehicle doors to drop.
2.
Erosion: This is generally due to the oxidation caused by the mud deposit and dirt; or the rust
caused by lack of anti-erosion processing after welding; or erosion caused by chemicals. This type
of damage usually occurs between the plate work pieces, in overlapped parts of spot-welded
pieces, and at other similar places.
3.
Cracks or breaks: The metal plates may develop fatigue under repeated inner/outer stress where
the stress concentrates and the structure is the weakest, causing cracks and even breaks.
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