TM-9-2815-205-24
6V53/6V53T ENGINES, DIESEL WITH CONTAINERS; MODEL 5063-5299, MODEL 5063-5392, MODEL 5063-5393 AND MODEL 5063-539L
TECHNICAL MANUAL; FIELD AND SUSTAINMENT MAINTENANCE
FEBRUARY 2013
TM-9-2815-205-24 - Page 61 of 856
FIELD MAINTENANCE
THEORY OF OPERATION
ENGINE SYSTEMS
General
The 6V53/6V53T Diesel Engine is an internal combustion power unit where the heat energy of fuel is converted
into work energy inside the cylinder. In a 6V53/6V53T Diesel Engine, air alone is compressed in the cylinder. After
compression, a charge of fuel is sprayed into the cylinder where ignition is accomplished by the heat of
compression.
Fuel System
The fuel system consists of a fuel pump, strainer (primary filter), filter (secondary filter), injectors, and related fuel
lines. The intense heat created by the high compression of the air immediately ignites the fine fuel spray. A
restricted fitting is located at the fuel return to maintain pressure within the fuel system. The fuel pump draws fuel
from the vehicle tank through the strainer and forces it through the filter. From the filter, fuel goes through the fuel
inlet passage in the cylinder head and fuel tubes into the injectors. The fuel passes through a filter element within
the injector to a chamber where it is metered, displaced, and atomized through the fuel injector spray tip into the
combustion chamber. Excess fuel not injected cools the injectors and returns through the fuel tubes to the fuel
tank.
Lubrication System
The lubrication system consists of an oil intake screen and tube assembly, oil pump, pressure regulator, oil filter,
bypass valve, and oil cooler. The gear type oil pump is bolted to the back of the lower front cover and is driven
directly by the crankshaft. Lubricating oil is picked up from the oil pan by the pump. From the pump, it passes
from the lower front cover through short gallery passages in the cylinder block to the oil filter adapter plate. From
the adapter plate, oil flows through the oil filter, through the oil cooler, back through the lower front cover, and into
the cylinder block oil galleries for distribution to the various engine bearings. The drains for the cylinder heads and
other engine parts lead back to the oil pan. Clean engine oil is assured by a replaceable oil filter. Should the filter
become clogged, oil will flow through a bypass valve in the adapter plate directly to the oil cooler. If the oil cooler
becomes clogged, oil will flow directly through a bypass valve in the lower front cover to the cylinder block oil
galleries. A regulator valve located in the lower front cover maintains a stabilized oil pressure at all engine
speeds.
Cooling System
The engine cooling system includes a centrifugal-type water pump, oil cooler water jacket, thermostat housing,
water manifold, bypass line, and cylinder block water jacket. The radiator and fan are located in the cooling
system of the vehicle. The water pump draws coolant from the radiator and circulates it through the oil cooler,
cylinder block, and cylinder heads to the thermostat housing. During the warm-up period, the thermostat blocks
coolant flow to the radiator. During this period, the pump circulates the coolant through the bypass system to the
cylinder block and cylinder heads. As the coolant reaches the designated operating temperature, the thermostat
opens and the coolant is circulated through the radiator.
Air Induction System
The air induction system consists of a blower, cylinder block air box, cylinder liner intake ports, and exhaust valve
ports. All engines, except model 5063-5299, also have a turbocharger. The blower forces air into the cylinders
(called scavenging) and sweeps out the burned gases through the exhaust valve ports. This air also cools the
TM 9-2815-205-24
0003
0003-1
Back to Top
