Hydraulic System; Overview - Yale A7S1 Service Manual

8000 YRM 2199
NOTE: If the forklift truck is kept without operating for
a long time, it is required to lift the mast cylinder 2-3
Forklift Truck Tonnage
Equipped Engine
Main Pump
Multi-way Adjusting Pressure
Valve
Bypass Valve
Lift Cylinder Cylinder Inner Diameter
Cylinder Inner Diameter
Tilt Cylinder
Piston Rod Outer Diameter

OVERVIEW

The hydraulic system is composed of a steering
control unit, a multi-way valve, lift cylinders, tilt
cylinders, and Hydraulic hoses and or Hydraulic
Tubes, The power-take-off (PTO) of the engine drives
the steering control unit directly.

Hydraulic System

Type
Driving
Full load flow
No load flow
Model
Type
Pressure
Flow Rate
Type
Stroke
Type
Stroke
times at least every 10 days for lubrication
maintenance.
GLP/ GLP/
GDP20UX GDP25UX
Gear Type Gear Type
72 liter/min 72 liter/min
(19 gal/min) (19 gal/min)
78 liter/min 78 liter/min
(20.6 gal/min) (20.6 gal/min)
MFT04 MFT04
Double Spool Valve, with Overflow Valve, Bypass Valve, and
Inclined Auto-locking Valve, pilot valve load feedback
18 MPa 18 MPa
(2610.68 psi) (2610.68 psi)
11 MPa 11 MPa
(1595.42 psi) (1595.42 psi)
12 liter/min 12 liter/min
(3.2 gal/min) (3.2 gal/min)
Single Act Piston Type, with Shutoff Valve, one-way valve and
Φ50 mm Φ50 mm
(2.0 in.) (2.0 in.)
(2nd-grade Standard Mast at 3m Lifting Height) 1495mm
(Varying along with Type of Mast and Lifting Height)
Double Acting Double Acting
Cylinder Cylinder
Φ70 mm Φ70 mm
(2.8 in.) (2.8 in.)
Φ32 mm Φ32 mm
(1.3 in.) (1.3 in.)
122 mm 122 mm
(4.8 in.) (4.8 in.)
Because the pump housing and pump cover are made
from aluminum, they are light and sturdy. The active
gear and the passive gear each have two shafts that
are individually installed on the pump housing
bearings. These bearings are made of special
material, to bear the radial load of the gear and also
serve as the baffle seats for the gear ends.
Hydraulic System
GLP/
GDP30UX
PSI 4G64 2.4L
Gear Type
Engine driven
72 liter/min
(19 gal/min)
78 liter/min
(20.6 gal/min)
MFT04
18 MPa
(2610.68 psi)
11 MPa
(1595.42 psi)
12 liter/min
(3.2 gal/min)
lower buffer
Φ56 mm
(2.2 in.)
Double Acting
Cylinder
Φ80 mm
(3.1 in.)
Φ35 mm
(1.4 in.)
141 mm
(5.6 in.)
GLP/
GDP35UX
Gear Type
82 liter/min
(21.7 gal/min)
88 liter/min
(23.2 gal/min)
MFT04
18 MPa
(2610.68 psi)
11 MPa
(1595.42 psi)
12 liter/min
(3.2 gal/min)
Φ63 mm
(2.5 in.)
Double Acting
Cylinder
Φ80 mm
(3.1 in.)
Φ35 mm
(1.4 in.)
141 mm
(5.6 in.)
41