Komatsu Galeo PC800-8 Shop Manual page 353

30 Testing and adjusting
2. Measuring work equipment circuit oil pressure
1) Measuring normal relief pressure
a The case where the boom cylinder is set
to the stroke end is explained below.
i) Start the engine and set the working
mode switch to the P-mode position.
ii) Run the engine at high idle, relieve each
cylinder singly at the stroke end, and
measure the oil pressure.
a The main relief valves of the right and
left control valves relieve on the low-
pressure setting side.
a If the boom cylinder is relieved at the
LOWER stroke end, the safety-suction
valve on the boom head side of the right
4-spool control valve relieves on the low-
pressure setting side (The set pressure
of the safety-suction valve is lower than
that of the main relief valve).
2) Measuring relief pressure during heavy lift
operation
a The case where the boom cylinder is set
to the stroke end is explained below.
i) Start the engine and set the working
mode switch in the P-mode position.
ii) Turn the heavy lift switch ON.
iii) Run the engine at high idle, relieve the
boom cylinder singly at the RAISE stroke
end, and measure the oil pressure.
a The heavy lift function operates only
when the boom RAISE operation is per-
formed singly.
a The main relief valves of the right and
left control valves relieve on the high-
pressure setting side.
3) Measuring relief pressure during machine
push-up operation
i) Start the engine and set the working
mode switch in the P-mode position.
ii) Turn the machine push-up switch ON.
iii) Run the engine at high idle, relieve the
boom cylinder singly at the LOWER
stroke end, and measure the oil pres-
sure.
a Since the set pressure of the safety-suc-
tion valve on the boom head side of the
right 4-spool valve rises higher than the
set pressure of the main relief valve, the
main relief valve relieves on the low-
pressure setting side.
PC800, 850-8
3. Measuring swing circuit oil pressure
1) Start the engine and set the working mode
switch in the P-mode position.
2) Turn the swing lock switch ON.
3) Run the engine at high idle, relieve the
swing motor, and measure the oil pressure.
a The safety valves of the front and rear swing
motors relieve. (The set pressure of the safe-
ty valves is lower than that of the main relief
valve.)
SEN00788-02
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