Model
Maximum
Capacity
A1
B1
D1
D2
A2
B2
B3
B4
Dead load
kg
Outer Width
mm
Length
mm
Lowest
Position mm
Highest
Position mm
Inner Width
mm
Length mm
Length mm
Length mm
Approx.
kg
BM40M
4000
520
1070
82.5
202.5
214
992
759
410
155
MB40LL
4000
685
1220
82.5
202.5
379
1139
906
414
175
BM40L5
4000
685
1600
82.5
202.5
379
1519
1284
414
220
BM50L4
5000
685
1500
85
205
285
1432
1197
416
260
BM50L6
5000
685
1800
85
205
285
1732
1496
416
300
BM50L7
5000
685
2000
85
205
285
1932
1695
416
320
● Lifting Circuit
Pumping of the handle sends
hydraulic oil from the oil tank to the
cylinder, allowing lifting to occur.
The cone prevents oil back flow,
and prevented by a cone.
● Lowering Circuit
Operating the lowering level
pushes the cone, causing the
hydraulic oil to flow from the
cylinder into the oil tank and
allowing lowering to occur.
Problem
Cause
Action
Store
Servicing
Will not lift
Insufficient hydraulic oil
Replenish hydraulic oil supply
Pressure pin stuck
Overhaul or exchange pressure pin
〇
Valve spring damaged
Replace valve spring
〇
Faulty steel ball sheet
Remove foreign material
〇
If cylinder base is damaged
〇
Too much pumping
required
U packing deterioration
Replace U packing
〇
Raises light loads but
not heavy loads
Rough steel ball sheet surface
Seating surface punching
〇
Damaged steel ball
Replace copper ball
〇
Lifts when pumping,
but lowers when
turning handle
Foreign material caught between cone
and cone sheet
Remove foreign material
〇
Damaged valve spring
Replace valve spring
〇
Lowers on its own
(Natural Lowering)
U packing deterioration
Replace U packing
〇
Faulty seal between cone and cone
sheet
Seating surface punching or replace
〇
Faulty O ring seal in cone sheet
Replace O ring
〇
Will not lower
Pressure pin stuck
Overhaul or exchange pressure pin
〇
Faulty adjustment of lowering pedal
section
Adjust lowering adjustment dial
*Some repairs require a very high level of expertise, so be sure to contact your dealer in those cases.
Unit Specifications and Dimensions
● Minimum rotation radius =overall length
－
105mm
Cylinder
Oil tank
Pump cylinder
Cylinder
Oil tank
Pressure pin
Cone (lowering valve)
Steel ball
Lower pedal part
Release spring
Relief presser
Relief plunger
Pump cylinder
Troubleshooting