6-58
SPECIFICATION
Oil temperature (40~50˚C)
Gauge and tool
Gauge 0~35 MPa (0~350 bar, 0~5000 psi)
M : System (main) relief valve
R : Bucket rollback relief
D : Bucket dump relief
U : Boom raise relief
Install fitting and pressure gauge to test
port in pump delivery line.
Install temperature reader.
(see temperature reader installation
procedure in this group)
Heat hydraulic oil to specifications.
(see hydraulic oil warm up procedure in this
group)
To check the system relief (M), run engine
at high idle. Lower boom to bottomed
position.
Slowly activate boom down function while
watching pressure gauge. If pressure is not
to specification, loosen lock nut on system
relief valve (M) and adjust to specification.
Do not adjust the system relief valve
above 280 kg/cm
2
(3980 psi). Damage to
the pump will result from excessive
pressure settings.
6. LOADER SYSTEM AND PORT RELIEF
VALVE PRESSURE TEST
·
·
1)
2)
3)
4)
※
Relief valve Engine speed
Relief pressure
System (M)
LS relief valve
High
280
±
5 kg/cm
2
(3980
±
70 psi)
Boom
raise (U)
Low
340
±
10 kg/cm
2
(4840
±
140 psi)
Bucket
rollback (R)
Low
340
±
10 kg/cm
2
(4840
±
140 psi)
Bucket
dump (D)
Low
HL955/XTD:
300
±
10 kg/cm
2
(4270
±
140 psi)
HL955TM:
150
±
10 kg/cm
2
(2130
±
140 psi)
M
R
U
D
a1
a2
b1
b2
MCV
Main pump
Hyd tank
757F6WE30
Summary of Contents for HL955
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