EP Equipment CPD30L1-B, Service Manual

Page: 83 / 235

71
REV. 05/2020
HYDRAULIC SYSTEM
7
7.1 Overview
The system pressure of the entire hydraulic
system pressure is provided by hydraulic power
unit system, which is used for lifting. While the
hydraulic power unit is equipped with a relief
valve to ensure that the entire system pressure
is always within the safety limits that can lift the
maximum load capacity.
Solenoid valve on the valve body is used for the
control of lowering. Throttle valve is used for the
control of lowering speed. Inlet is equipped with
a filter to prevent the impurities in the hydraulic
oil from entering into the pump.
Oil pipeline explosion-proof valve is installed at
the hydraulic cylinder to prevent the free falling
of the load after system failure.
Hydraulic Schematic Diagram is as shown in
Fig3131-40001SM;
See Section 7.11 for hydraulic symbol descripti-
ons.
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Lower the mast to the bottom, remove the air
filter on cylinder, observe the oil level with the
oil dipstick. When adding hydraulic oil, please
use hydraulic oil of the same specifications.
When the mast occasionally jitters, that may
be leaks in the cylinder, or there could be
leaks on the valve body. Dismantle and clean
(to clean with hydraulic oil of the same spe-
cifications) the valve on the valve body, disch-
arge the foreign bodies within the valve body
through repeatedly lifting and lowering of the
mast.
If hydraulic oil is becoming less, please tho-
roughly check the hydraulic system for leaks.
Disassembly of cylinder needs to be perfor-
med in a clean environment. Before removing
the cylinder, the stains on the cylinder must
be removed first. Carefully remove the piston
rod to prevent the cylinder wall from being
scratched by its end surface or damaged
part. Every time when replacing the cylinder,
also replace the cylinder seals.
Hydraulic Oil
Hydraulic oil for truck:
Specifications: Anti-wear Hydraulic Oil L-HM46.
* For cold storage: Low Temperature Anti-wear
Hydraulic Oil L-HV32.
Hydraulic Seals
The seals installed within the cylinder are made
of rigid polyurethane. The deformation during
assembly due to compression will not cause a
permanent deformation.
When assembling, pay attention to prevent the
seals from being broken, rolled and undercut.
Assembly Instructions
The tools used to install the seals must be made
of soft metal or suitable plastic, without burrs
and sharp edges on surfaces. It is prohibited
to use the tools that can easily damage the
surface of seals, such as, screwdriver or other
similar tools with hard front edges.
Where the hydraulic seals to be installed should
be free of burrs, sharp edges and cracks. If the
installation of seals needs to cross sharp edges,
grooves or cuts, protective devices must be
used for protection. Before installing, lubrication
should be performed to the seals and the
mounting positions first.
The lubricant used during assembly must be of
the same specifications with the hydraulic oil
used in the vehicle.
CAUTION