Toro Groundsmaster 328-D, Service Manual

Page: 53 / 402

Preparation for Engine Repair
1. Before cleaning and disassembly, carefully check for
problems that cannot be found after the engine has
been cleaned or disassembled (e.g. oil leaks from
cracked components, gaskets or loose fittings, dam-
aged air cleaner or breather hoses that could cause
cylinder wear, etc.). Make a note of any problems that
you find.
2. Clean or wash the engine exterior thoroughly before
disassembly.
IMPORTANT: Do not spray water on a hot engine.
Injection pump seizure or other failures could
result.
3. Do not disassemble or remove parts that do not
require disassembly.
4. Disassemble the engine in proper order, arranging
the parts the disassembled parts neatly. Apply clean
engine oil to disassembled parts, as necessary to pre-
vent rust.
5. Keep the work area clean; dirt causes engine failures.
6. Be very careful when working on fuel system compo-
nents. Cover the work area with clean paper. Store
components of the nozzles or injector pump in clean fuel
oil. Do not allow components to strike each other or
other objects. Wet hands with clean diesel fuel before
handling these parts.
Engine Compression
The time interval to overhaul the engine can most
accurately be determined by regular and systematic
cylinder compression measurement. (See Compres-
sion Test in the Testing section of this chapter.)
Cylinder and Cylinder Block Overhaul
Before removing any parts, disassembly or overhaul of
the Mitsubishi engine, it is very important to understand
the nature and probable cause of the problem that made
an overhaul necessary.
When the engine trouble is caused by worn cylinders,
rings or valves, one or more of the following symptoms
will occur:
1. Low engine power, and a decrease in compression
pressure.
2. Increased fuel consumption.
3. Increased lubricating oil consumption.
4. Poor engine starting.
5. Loud noises in the engine.
It is important to find the cause of the engine failure
before beginning repair. Symptoms 2 and 3 in the above
list can be a result of excessive fuel injection, improper
injection timing, or nozzle and injection pump wear. Poor
starting may be a result of electrical problems. Noises
may be associated with a mechanical part outside the
engine. Excess fuel or oil consumption may be the result
of leaks. (See the Troubleshooting section of this chap-
ter.)
Another indicator of the need for an overhaul is oil
consumption. Make sure the engine does not leak oil.
when the oil consumption between the oil change main-
tenance interval is approximately 1-1/2 times normal
(150%), engine overhaul should be considered.
With a good knowledge of how the engine operates,
access to maintenance and compression test records,
and information in the Troubleshooting section of this
chapter, unnecessary disassembly and inspection can
be eliminated.
Groundsmaster
®
300 Series Page 4 - 25 Preparation for Engine Repair