Main Relief Valve Pressure Test
This main relief pressure should be checked while
running the vibratory system. For this reason, it
is recommended that the drum be placed on tires
to simulate an uncompacted soil condition. The
hydraulic oil temperature should be 38° C (100° F).
Make sure the parking brake is applied, and the propel
control lever is in the NEUTRAL position.
Vibratory Flushing Valve.
(1) High amplitude test port.
Connect a 60 000 kPa (8700 psi) pressure gauge to test
(2) Vibratory control switch. (3) Vibratory selector switch.
Move vibratory selector switch (3) to the HIGH
Start and run the engine at high idle. Engine rpm
should be 2350 50 rpm.
Look at the gauge and depress vibratory control switch
(2) to the ON position to start the vibratory system.
The force needed to overcome the inertia of the
weights will cause the pressure in the vibratory
system to momentarily reach the high amplitude
relief valve setting. Observe the gauge when
starting the vibratory system and record the
The high amplitude relief valve setting should be 29 000
to 33 100 kPa (4200 to 4800 psi).
(4) High amplitude relief valve.
If the high amplitude relief valve setting is not correct,
high amplitude relief valve (4) must be replaced.