Golden Dragon XML6125CLE, Repair Manual

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General Instructions GI-6126J12-01
GI-12

Introduction of bus oils and fluids
1. Bus lubricants
 Engine lubricating oil
1) Lubricating oils influence the main working properties of the engine.
a) Viscosity and viscosity-temperature characteristic: viscosity refers to the extent of
shearing force between layers of flowing lubricating oils; viscosity-temperature
characteristic refers to the changes of viscosity of lubricating oils with the changes of
temperature.
b) Foaming characteristic of lubricating oils: it refers to the generation of foams because of
the difficult separation of gases infiltrated into the oil due to the surface strains of
lubricating oils.
c) Stability of lubricating oils: it refers to the lubricating oil’s ability to keep its physical and
chemical properties stable for a long term, including resistance to vaporization, shearing
force, atmospheric oxidation and high-temperature oxidation.
d) Anticorrosion of lubricating oils: the lubricating oil’s ability to protect the targets from
corrosions.
e) Static dispersivity of lubricating oils: lubricating oils are highly capable of dispersing
gums, paint films and other solid substances so that they can be recycled together with the
lubricating oils and removed by the filter.
f) Resistance to abrasion: the lubricating oil’s ability to prevent the oil film from being
damaged.
2) Designation and variety of commonly used lubricating oils
Variety Viscosity and designation
SC 5W/20 10W/30 15W/40 30
40
SD, SD/CC 5W/30 10W/30 15W/40 30
40
SE, SE/CC 5W/30 10W/30 15W/40 20/20W
30 40
SF, SF/CD 5W/30 10W/30 15W/40 30
40
CC 5W/30 5W/40 10W/30 10W/40 15W/40 20W/40 30
40 50
CD 5W/30 5W/40 10W/30 10W/40 15W/40 20W/40 30
40
a) In the ‘variety’ column, the first letter ‘s’ indicates lubricating oils for gasoline engine and
‘C’ indicates lubricating oils for diesel engine; the second letter indicates the grade of the
oil in alphabetic order with C, D, E and F representing a rising grade.
b) In the ‘variety’ column, two letters indicate single-grade lubricating oils that are only
applicable to one type of engine; four or more letters that are separated by a ‘/’ (e.g.
SE/CD) indicate multi-grade general-purpose lubricating oils (applicable to both gasoline
engine and diesel engine).
c) In the ‘Viscosity and designation’ column, an Arabic number followed by a ‘W’ indicates
the viscosity level that enables engine startup at a certain low temperature in winter; an
Arabic number without a ‘W’ indicates lubricating oils not for winter use. The number
indicates the highest temperature for the lubricating oil;
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