Mega MMP4, Maintenance Manual

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4-1
MMP4-CAT(T4)-MX-2
26 Feb 2014
SECTION 4
Basic Hydraulics System
Contents
DESCRIPTION
The MMP4 hydraulic system originates at a hydraulic
pump coupled to a CAT C2.2T Diesel engine. The
system draws hydraulic oil from a hydraulic tank
mounted at the rear of the MMP4 frame through an
inlet screen inside of the tank and a shut off valve on
the outside of the tank. The hydraulic pump moves
the oil to a hydraulic control valve mounted to the
right side of the unit. The control valve diverts and
regulates the oil flow and pressure through the
MMP4 system. The Hydraulic control valve is used to
control the raising and lowering of the 2 hydraulic
cylinders attached to the inlet and discharge booms.
The hydraulic control valve also controls the
hydraulic drive motor inside of the water pump at the
end of the inlet boom; this control feature is
equipped with a detent to allow the lever to stay in
the ON position during water pump operation, and is
equipped with a pressure relief valve to protect
against over-pressurization of the hydraulic system.
The return hydraulic oil is passed through a hydraulic
oil filter, oil cooler, and then a diffuser mounted
inside of the hydraulic oil tank.
HYDRAULIC TANK ASSEMBLY
DESCRIPTION
The hydraulic tank consists of an inlet screen, return
oil diffuser, internal baffle, shut off valve, oil level
sight gauge, reservoir cap and breather. The system
draws oil from the bottom of the tank through an
inlet screen to pre-filter the oil. The shut off valve (if
equipped) holds the oil inside of the tank when
servicing the hydraulic system. The sight gauge is
used as a visual indicator of the hydraulic oil quality
and quantity. The Internal baffle allows for oil
movement with in the tank to evenly distribute the
return oil trough out the reservoir. The return diffuser
inside of the hydraulic tank just below the normal oil
level reduces the potential for hydraulic oil foaming
in the tank. The reservoir cap and breather allow
filling of the hydraulic tank and prevent dirt and
debris from entering the hydraulic system.
INSPECTION
1. Inspect hydraulic oil tank for security, damage,
and leaks.
Description .........................................................................4-1
Hydraulic Tank Assembly ..............................................4-1 Hydraulic Pump................................................................4-2