Baroness LM551, Service Manual, Page: 66 / 213

Measurement
Note
The most effective way of solving problems in
the hydraulic system is to use a measuring
instrument such as a pressure gauge to
measure the hydraulic pressure in the faulty
hydraulic circuit.
Before pressure measurement
Important
Before concluding that the problem in the
hydraulic system is caused by the hydraulic
equipment, every part of the hydraulic system
must be checked for issues related to level of
hydraulic oil, oil filter, loose fasteners, lack of
adjustment, and so on.
Note on pressure measurement
Warning
As mentioned in the measurement procedure,
the use of a pressure gauge not meeting the
pressure measurement standard may result in
damage to the pressure gauge or leakage of
high-pressure oil.
Be extremely careful on high-pressure oil as it
may pierce your skin, resulting in personal
accidents.
Important
Carry out hydraulic measurement with two or
more persons.
One person should be in the driver
’
s seat to
operate the machine and the other person
should engage in measurement and
recording.
Always clean the machine before pressure
measurement.
Remember that the machine must always be
kept clean for pressure measurement.
Contamination may lead to clogging or
breakage of the hydraulic circuit.
Review the measuring method before
starting measurement.
Before measurement, check for poor
adjustment, clogging, or breakage. 1.
2.
3.
Warm up the hydraulic oil before starting
pressure measurement.
Warning
Be sure to depressurize the hydraulic system
before inspecting or repairing it.
When hydraulic equipment is removed, cap
or plug it to prevent contamination of the
hydraulic system.
When using a measuring instrument such as
a pressure gauge, connect the in/out hoses
correctly.
Never connect the other way round to
prevent breakage of the hydraulic system
and measuring instrument.
Screw in the hydraulic fitting by hand until it
touches the other side lightly, then fasten
with a wrench.
Fit hoses and measuring instruments in such
a way as to avoid contact with moving parts
of the machine.
After connecting a measuring instrument,
check the amount of hydraulic oil in the
hydraulic tank.
Check to see that the engine is in good
condition.
Carry out pressure measurement with the
engine running at maximum speed.
In case there is any problem in the traveling
circuit, carry out the following measurement.
Charge relief valve pressure
Traveling relieve valve pressure
In case there is any problem in the up/down
circuit, steering circuit, or reel rotation circuit,
carry out the following measurements.
Relief valve pressure of each circuit
Make sure that there is no oil leakage after
reinstalling the removed hydraulic parts to
their original positions.
In the event of oil leakage, stop the engine
and repair the oil leak.
Check the amount of hydraulic oil in the
hydraulic tank.
Add oil if necessary.
Always clean the machine after pressure
measurement.
4.
5.
6.
7.
8.
9.
10.
11.
[1]
[2]
12.
[1]
13.
14.
15.
LM551
Hydraulic System
Page 4-28
Measurement