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 to the low amplitude
relief valve setting. Observe the gauge when
starting the vibratory system. The highest
reading on the gauge is the low amplitude relief
For early pumps, the low amplitude relief valve setting
should be 21 360 to 25 500 kPa (3100 to 3700 psi). For
later pumps, the high amplitude relief valve setting
should be 29 000 to 33 100 kPa (4200 to 4800 psi).
Vibratory Pump (Early).
(4) Low amplitude relief valve.
Vibratory Pump (Later).
(4) High amplitude relief valve.
If the low amplitude relief valve setting is not correct, low
amplitude relief valve (4) must be replaced.
When a new low amplitude relief valve is installed,
check the pressure setting again. If it is correct, stop
the engine and remove all tooling.