Page 37 - Foton Workshop Manual - Auman EST-M

Introduction - Cleaning regulations IN - 31

It must be specially careful to clean the engine parts (especially partially assembled engine) with grinding IN
supplies. The friction and cleaning supplies have many forms and dimensions. They includes aluminium oxide
particles, diamond sands, sands or other similar hard materials.
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These particles are harder than most parts of engine. If they are pressed onto softer materials, they will

damage these materials and embed in these materials due to their higher hardness. During the use of these
grinding supplies, these materials can fall off from the grinding supplies. In case of using these supplies on the EG
power equipment, their fine particles will drop out around the engine.
If these particles fall between two moving parts, it may lead to damages of engine parts. TR
If the particle diameter is smaller than the gap between the static moving parts (stopping of engine), but the

diameter is bigger than the moving clearance, the part will be damaged during its relative movement (starting
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of engine). When the engine runs and has oil pressure, the particles with their diameter below bearing

clearance may pass through two parts, but they can’t cause the part damages and then they’re hindered by an
oil filter. However, the particles with their diameter over bearing clearance will grind off the materials from FR
some part, and may embed in this part. Once they embed in some part, the other part will be ground off until
both parts can’t contact each other. If the damages have obvious influences on oil film, both parts will contact
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each other directly, and cause premature wears or failure due to no effective lubrication.

The friction particles may spread out while cleaning, and it’s very important to prevent these particles from
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entering into the engine. It should be so for the oil port and oil duct hole, especially these holes downstream of
oil filter. Block the holes. Don’t try blowing off the friction particles and chippings with compressed air,
because it often blows the chippings further into oil duct in this way. BW
All the original sealing gasket materials must be removed from the part sealing gasket surface. However, it’s
not required to clean and grind the sealing gasket surface until its machined mark is ground off. Excessive
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sandpaper grinding or polishing may damage the surface of sealing gasket. Many new sealing gaskets

compression molded (steel substrate has a seal affixed on steel plate). Remove the sealing materials with low
adhesive ability with a scraper or putty knife. It’s usually a waste of time to clean the surface of sealing
gasket with molded edges via a grinding plate or sandpaper.
Caution

It may damage the cylinder liner and make it unable to use to excessively grind or mill the carbon ring
on the top of cylinder liner via sandpaper. Its surface layer may be damaged, and the friction particles
may be pressed into cylinder liner materials, thus it may cause the premature wears of air cylinder or
failure of piston ring.
Adopt tapes or plugs to close or block all the inner openings connecting to any part before using the
grinding plate or steel wire brush. If the power tools with grinding plates must be really used for time
reasons, seal the oil duct with a tape or plug, and try to clean the most of surface with this tool, but it’s
required to clean around the oil hole, so as to avoid oil duct pollution. Then remove the tape or plug,
and don’t clean other sections carefully with a tool. Don’t blow the chippings out of assembled oil
duct with compressed air! It possibly has an exactly opposite effect, and it may blow the chippings
further into oil duct. If both ends of oil duct can be opened and allow for applying the compressed air,
but in reality this happens rarely for assembled engine.
3. Seal surface

The purpose of cleaning the sealing gasket surface is to remove any sealing gasket material, and not to
re-grind the sealing gasket surface of part.

It’s not recommended to apply any liquid detergent of sealing gasket with special brand. In case of applying

the liquid detergent, check its operating instructions to ensure no damages of materials to be cleaned.

IN-031