Method For Replacing Def Tank Breather Element; Method For Checking Alternator Belt Tension And Replacing Alternator Belt - Komatsu PC490LC Installation And Instruction Manual

MAINTENANCE PROCEDURE

METHOD FOR REPLACING DEF TANK BREATHER ELEMENT

Do not replace the element immediately after engine is stopped.
NOTICE
• Komatsu recommends using Komatsu genuine parts for replacement parts.
• If the machine is operated without DEF tank breather element attached, or with the element other
than Komatsu genuine parts, foreign materials may enter into DEF pump and DEF injector which
will cause failure of the machine. Never operate the machine without DEF tank breather element at-
tached, nor use the element other than Komatsu genuine parts.
• Do not flush DEF tank breather element. Flushing or regenerating of it will degrade the performance
of element, and will cause the breakage of DEF tank. Never reuse the DEF element.
• Always stop the engine and clean around DEF tank before replacing.
• After the engine is stopped, DEF system devices automatically purge DEF in DEF injector and DEF
pump and return it to DEF tank to prevent malfunction of the devices caused by freezing of DEF or
deposition of urea.
After the engine is stopped, the devices are operated for a few minutes. Replace the element after
DEF system devices stop.
• Improper assembly of DEF tank breather element may cause leakage of DEF. Replace the element in
the correct procedure.
1.
Open DEF tank cover at the right of the machine upward.
2.
Remove nut (2) of breather assembly (1) at the top of DEF
tank, then remove cover (3).
3.
Replace breather (4) with a new one.
4.
Install cover (3) and nut (2).
In order not to damage the threaded portion of nut, tighten
nut (2) by hand until it is seated, then tighten it 15 to 25° by
using a tool.
NOTICE
If breather assembly (1) is removed for replacement,
apply a tool to bolt (5) and tighten it.
Tightening torque: 6.5 to 8.5 Nm{0.66 to 0.87 kgm}
5.
Close DEF tank cover at the right of the machine.
METHOD FOR CHECKING ALTERNATOR BELT TENSION AND REPLACING AL-
TERNATOR BELT
Special tools are required for inspection and replacement of the alternator belt. Ask your Komatsu distributors
for inspection and replacement.
REMARK
As the auto alternator belt tensioner is installed, no belt tension adjustment is required.
4-64
k k
WARNING
MAINTENANCE