Weichai America Corp.
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3.1.5 Cylinder head inspection and maintenance
1.
Before removing the cylinder head cover first check cylinder head and body joints with no
water leakage, oil leakage, air leaks and other abnormal phenomena. If any such problems,
replace the new cylinder head gasket to see if the problem is solved, the cylinder head gasket
disassembly method, see this section.
2.
Check the cylinder head appearance, fine check cylinder discoloration and cracks, if cracks
are found, the color inspection
3.
Before disassembly, check whether there is any oil leakage in the oil inlet pipe and check
whether the oil inlet pipe itself is cracked, worn or corroded. If there is a crack, you need to
change the oil into the oil pipe. Analysis of the corrosion affecting reliability is needed Cause
and replace the new lubricant into the tubing. If the oil leakage appears in the hollow bolt, you
need to replace the hollow bolts, combination ferrules, tighten, and then check for oil leakage.
4.
Before disassembly and disassembly of the valve, check the valve sinking amount, the valve
sinking amount is the vertical distance from the bottom surface of the valve cylinder to the
bottom of the cylinder head, and the difference between the valve sinking amount
measurement value and the valve sinking amount requirement value can indirectly reflect the
valve and valve seat Wear level. You can use the depth micrometer to measure the amount of
valve depression, as shown in Figure 4-13
：
Figure 3-5 Depth micrometer
Refer to Table 3-3 for the required value of valve sinking. If the amount of valve sinking
exceeds the allowable range, the cylinder head needs to be replaced to ensure the reliability of
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
Document Courtesy of Fly Parts Guy Co.
www.FlyPartsGuy.com
