MCi Crusader II 1989 Maintenance Manual page 298

Date
1-1-89,
Page·_. __
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MC-9 MAINTENANCE MANUAL
:onnect height control valve links and pull do,wn to vent air from
rear suspension bellows.
2. Drain the engine cooling system as directed in Section 6
of this manual, remove the cooling blower drive belt
3. Open drain cock and vent air from the brake system.
Disconnect the propeller shaft as outlined in Section 14 of this
manual. Disconnect transmission and clutch operating linkage.
Disconnect clutch cable. Disconnect throttle linkage.
4. Disconnect exhaust muffler slip joint Disconnect air lines
to air compressor governor and fast idle air cylinder.
5. Disconnect electrical connection to speedometer unit (if
used), starting motor, starting motor solenoid, alternator, engine
controls, tachometer (if used), oil pressure and engine tempera-
ture sending units. If the engine is an electronically controlled
model (DOEC), disconnect the main DDEC hamess from the
electronic control module which is on top and to the front of the
engine.
6. Disconnect and remove cooling system connections to
radiators, surge tank and coach heating system. Disconnect
fuel supply and return· lines. Remove connections between air
cleaner and engine air inlet horn.
7. Remove the air conditioning compressor drive belts.
Raise the coach approximately 4-6". (101.6-152.4 mm) above
the road height.
8. Remove the clamp bolts securing the engine sub-frame to
the coach body. Position the dolly under the engine cradle.
Lower the coach body <;>nly sufficiently to transfer the we:ght of
the engine onto the dolly.
CAUTION: Due to the minimum clearance
between the air compressor and the top of
the engine compartment, extreme care
should be used to lower the coach body
only enough to free the engine cradle.
Clearance between engine cradle and
coach engine mounting rail should be
1/a• ¼''
(3.1-6.3 mm).
9. Remove engine assembly as a unit, carefully withdrawing
it from the rear of the coach. To reinstall, the procedure is the
reverse of the above.
, 0. Refill cooling system. If engine fuel system has been
drained, it will aid restarting if fuel filters are filled with fuel oil.
Remove vent plugs and pour fuel oil into filter body until filters
are full.
11. Start engine and check operation. Check fuel and cool-
ing system connections for leakage. Test operation of engine
controls and accessories.
DIESEL ENGINE LUBRICATING OILS
The oil capacity of coaches equipped with a 6V-92 engine is
30 U.S. quarts (28.28 liters). Coaches equipped with an 8V-71 or
BV-92 engine have an oil capacity of 32 U.S. quarts (30.28
liters). Oil is added through the oil fill tube (figure 8-2).
All diesel engines require heavy-duty lubricating oils. Basic
requirements of such -oils are lubricating quality, high heat
resistance and control of contaminants.
Figure 8-2. Oil Filler Tube.
The reduction of friction and wear by maintaining an oil film
between moving parts is the primary requisite of a lubricant.
Film thickness and its ability to prevent metal-to-metal contact
of moving parts is related to oil viscosity. The optimums for
6V-92, 8V-92 and BV- 71 diesel engines are SAE 40 or 30 weight
oil.
Temperature is the most important factor in determining the
rate at which deterioration or oxidation of the lubricating oil will
occur. The oil should have adequate thermal stability at ele-
vated temperatures, thereby precluding formation of harmful
carbonaceous and/or ash deposits.
The piston and compression rings must ride on a film of oil to
minimize wear and prevent ring seizure. At normal rates of
consumption, oil reaches a temperature zone at the upper part
of the piston where rapid oxidation and carbonization can
occur. ln addition, as oil circulates through the engine. it is
continuously contaminated by soot, acids, and water originat-
ing from combustion. Until they are exhausted, detergent and
dispersant additives aid in keeping sludge and varnish from
depositir,g on engine parts. b·ut such additives in excessive
quantities can result in detrimental ash deposits. If abnormal
amounts of insolubles form, particularly on the piston in the
compression ring area, early engine failure may result.
Oil that is carried up the cylinder liner wall is normally con-
sumed during engine operation. The oil and additives leave
carbonaceous and/or ash deposits when subject to the ele-
vated temperatures of the combustion chamber. The amount of
deposits is influenced by the oil composition. additive content,
engine temperature and oil consumption rate.