Dawson EMV 550 Owner's Manual page 14

continued - mounting instructions
HYDRAULIC HOSES - LAYOUT & CONNECTIONS
The pressure line is usually connected to the bucket ram "extend" circuit and the return line to the bucket
ram "retract" circuit. The third, and smaller, drain line is fed either directly back into the hydraulic tank on
the excavator, or connected to the breaker circuit return line. Excavators will rarely have the same fittings as
these on their bucket circuit so adaptor fittings must be used.
Connect drainline
directly to
excavator tank
Ensure all hydraulic connections are clean prior to fitting and that no contamination is introduced into the
hydraulic circuit during installation – this may cause internal component damage to the hydraulic system or
faulty operation of the vibrator or excavator.
If quick release couplings are installed on the excavator they should be replaced. It is strongly recommend-
ed that quick release couplings are not used for this application. For permanent installation ball valves can
be added to the excavator boom to ensure rapid changing between bucket and EMV hydraulic function. As
the bucket ram is no longer in use, it should be retracted and fastened down.
WARNING: THE DRAIN LINE MUST FLOW DIRECTLY TO TANK WITHOUT RESTRICTION. FAILURE TO
DO SO WILL RESULT IN THE HYDRAULIC DRIVE MOTOR BLOWING ITS CASING SEAL OR FRONT
CASING CASTING – THIS DAMAGE IS VERY COSTLY TO REPAIR.
The EMV is fitted with a motor case blow-off valve. This valve is effectively a check valve that vents some
oil to atmosphere should the motor case drain line pressure exceed approximately 6 bar. It is not a pressure
protection valve and is intended only as an early warning valve, giving a visual signal that something is
wrong. Any sign of this and use of the EMV should be halted immediately and the cause investigated.
The blow-off valve does not guarantee the motor will be protected in all circumstances!
14
excavator mounted vibrator
Connect to bucket
ram extend hose
Connect to bucket
ram retract hose