Terex TR60 Maintenance Manual page 256

Fuel System - Fuel Lines
Section 200-0040
The electronic fuel injector (13) is a lightweight,
compact unit that injects diesel fuel directly into the
combustion chamber. The amount of fuel injected and
the beginning of injection timing is determined by the
ECM. The ECM sends a command pulse which
activates the injector solenoid.
The injector performs four functions:
a - Creates the high fuel pressure required for efficient
injection.
b - Meters and injects the exact amount of fuel
required to handle the load.
c - Atomizes the fuel for mixing with the air in the
combustion chamber.
d - Permits continuous fuel flow for component
cooling.
Electronic fuel injectors are self compensating and
virtually eliminate engine tune-ups.
Note: Never apply 12 V directly to terminals on the
injector as it will burn out. Before removing injectors,
the fuel passages must be blown out to prevent fuel
flow from entering the cylinder head.
ECM cooling plate (10) is mounted in front of the ECM
on the LH side of the engine and absorbs heat
generated by the ECM. Fuel from fuel pump (6) outlet
line (8) flows through ECM cooling plate (10) to absorb
this heat.
Fuel cooler (14) is mounted on the front RH side of the
radiator and cools fuel returning to fuel tank (1).
Flexible fuel lines (2, 5, 8, 15 & 16) are used to
facilitate connection of lines leading to and from fuel
tank (1), and to minimize the effects of any vibration in
the installation. A check valve is incorporated in the
fuel supply line to maintain fuel pressure in the system.
The restricting check valve is designed to provide the
proper fuel system pressure under all conditions.
Note: Do not alter or substitute check valve since this
may alter engine performance and emissions.
Note: Do not use restricted fittings or valves anywhere
else in the fuel system.
When installing fuel lines, it is recommended that
connections be tightened only sufficiently to prevent
leakage of fuel; thus flared ends of the fuel lines will
not become twisted or fractured because of excessive
tightening.
2
OPERATION
Numbers in parentheses refer to Fig. 1.
Fuel is drawn from fuel tank (1) through primary and
secondary fuel filters (3 & 4, respectively) and enters
fuel pump (6). Leaving fuel pump (6) under pressure,
the fuel flows through ECM cooling plate (10) to the
engine cylinder head. The fuel flows to electronic fuel
injectors (13) in the cylinder head through passages
integral with the cylinder head. Surplus fuel exits at the
rear of the cylinder head just above the inlet, flows
through fuel cooler (14) and back to fuel tank (1).
MAINTENANCE
Every 10 Hours/Daily:
Make a visual check for fuel leaks at all engine
mounted fuel lines and connections, fuel cooler, and at
the fuel tank suction and return lines. Examine lines
for leaks and check all fittings, clamps and ties carefully.
Make sure that fuel lines are not resting on or touching
rotating components, heated surfaces including
exhaust manifolds or sharp edges. If fittings have
loosened or cracked, or if lines have ruptured or worn
through, take corrective action immediately.
Refill the fuel tank at the end of each day's operation
to prevent condensation from contaminating the fuel.
Every 250 Hours:
Replace the primary and secondary fuel filters as
follows:
Note: There is a fuel system shut off cock on the
discharge side of the secondary fuel filter. Closing this
valve will prevent loss of fuel prime at time of filter
replacement.
1. Close shut off valve at secondary fuel filter and,
using a strap type filter wrench, remove and discard
both the primary and secondary fuel filters from the
engine.
2. Fill the replacement filters and coat the gaskets
slightly with clean fuel oil as specified in Section
300-0020, LUBRICATION SYSTEM.
3. Start new primary fuel filter on the filter adaptor and
tighten it by hand until the gasket contacts the adaptor
fully with no side movement of the filter evident.
Tighten an additional 1/2 of a turn.
SM 1195 2-98