Advertisement
FOREWORD
12
4.
Repair Limit And Allowable Value
•
The size of a part changes because of wear and deformation while it is used. The limit of changed size is called the
"repair limit".
•
If a part is worn to the repair limit must be replaced or repaired.
•
The performance and function of a product lowers while it is used. A value below which the product can be used
without causing a problem is called the "allowable value".
•
If a product is worn to the allowable value, it must be checked or repaired. Since the permissible value is estimated
from various tests or experiences in most cases, however, it must be judged after considering the operating condition
and customer's requirement.
5.
Clearance Limit
•
Parts can be used until the clearance between them is increased to a certain limit. The limit at which those parts
cannot be used is called the "clearance limit".
•
If the clearance between the parts exceeds the clearance limit, they must be replaced or repaired.
6.
Interference Limit
•
The allowable maximum interference between the hole of a part and the shaft of another part to be assembled is called
the "interference limit".
•
The interference limit shows the repair limit of the part of smaller tolerance.
•
If the interference between the parts exceeds the interference limit, they must be replaced or repaired.
HANDLING OF FUEL SYSTEM DEVICES
●
The common rail fuel injection system (CRI) consists of more precise parts than the conventional fuel injection pump and
nozzles. If foreign matter enters this system, it can cause a problem. Use special care to prevent entry of foreign matter
when performing inspection and maintenance of the fuel system.
Be careful of the work environment.
●
Avoid replacing filters or repairing the machine in rain or high winds, or at places where there is a lot of dust.
Sealing openings
●
After any piping or equipment is removed, the openings should be sealed with caps, tapes, or vinyl bags to prevent any
dirt or dust from entering. If the opening is left open or is blocked with a rag, there is danger of dirt entering or of the sur-
rounding area being made dirty by leaking oil so never do this. Do not simply drain oil out onto the ground, but collect it
and ask the customer to dispose of it, or take it back with you for disposal.
Cleaning off dusts
●
Wash the system carefully with clean fuel if dusts enter the system.
Precautions for replacing fuel filter cartridge
●
Be sure to use the Komatsu genuine fuel filter cartridge.
●
Since the common rail fuel injection system (CRI) consists of more precise parts than the conventional fuel injection
pump and nozzles, it employs a high-efficiency special filter to prevent foreign matter from entering it. If a filter other
than the genuine one is used, the fuel system may have a trouble. Accordingly, never use such a filter.
PC490LC-10
HANDLING OF FUEL SYSTEM DEVICES
00
00-31 b
Advertisement
