Handling Fuel System Parts; Releasing Residual Pressure From Fuel System - Komatsu PC210-8 Shop Manual

30 Testing and adjusting

Handling fuel system parts

a Precautions for checking and maintaining fuel
system
The common rail fuel injection system (CRI)
consists of more precise parts than the con-
ventional fuel injection pump and nozzle. If for-
eign matter enters this system, it can cause a
trouble.
When checking and maintaining the fuel sys-
tem, take care more than the past. If dust, etc.
sticks to any part, wash that part thoroughly
with clean fuel.
a 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 nozzle, it
employs a high-efficiency special filter to pre-
vent 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.
PC210, 230, 240-8
1 Releasing residual pressure from
fuel system
a Pressure is generated in the low-pressure cir-
cuit and high-pressure circuit of the fuel sys-
tem while the engine is running.
Low-pressure circuit:
Feed pump – Fuel main filter – Supply pump
High-pressure circuit:
Supply pump – Common rail – Injector
a The pressure in both low-pressure circuit and
high-pressure circuit lowers to a safety level
automatically 30 seconds after the engine is
stopped.
a Before the fuel circuit is checked and its parts
are removed, the residual pressure in the fuel
circuit must be released completely. Accord-
ingly, observe the following.
k
Before checking the fuel system or remov-
ing its parts, wait at least 30 seconds after
stopping the engine until the residual pres-
sure in the fuel circuit is released. (Do not
start the work just after stopping the engine
since there is residual pressure.)
UEN00228-04
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