SANY SRT95C Off-Highway Truck. Service Manual

Overview

See Fig.1 for the numbers in brackets, unless

otherwise specified.

Note

: fuel tank capacity and oil technical

specifications are detailed in section 36.1
'LUBRICATION AND MAINTENANCE'.

Disassembly

See Fig.1 for the numbers in brackets, unless

otherwise specified.

WARNING

To prevent personal injury and property

damage, be sure wheel chocks and lifting

equipment are properly secured and of

adequate capacity to do the job safely.

Remove the parts and components as
following:
1. Position the vehicle in a level work area,
raise the body and install the body safety pins.
2. Apply the parking brake and switch off the
engine.
3. Turn the steering wheel in both directions
several times to relieve any pressure in the
steering system.
Block all road wheels.

4. Close fuel shut off valve at the fuel filters to

prevent loss of fuel prime at the engine.
5. Disconnect fuel liquid level sensor joint.
6. With a suitable container in position, remove
drain plug (12,Fig2) and drain fuel from fuel
tank (25). Reinstall drain plug when  fuel  tank
is completely drained.
7. Identify and  tag  fuel  lines  connected  to
fuel  tank  (25)  and  engine,  with  a  suitable
container available to catch leakage, loosen
the clamp(2,14)disconnect  fuel lines(3.15.16)
from fuel tank (25) and engine. Cap open line
ends to prevent entry of dirt.
8. Remove  bolts (9) ,  washers  (10) ,   bolt (4),
Connector (7), washers  (5,8) and articulating

Fuel Tank And Mounting

body (6), and remove Primary filter (11) from

engine.
9. Using a suitable lifting device, support fuel
tank (25)and take up any slack. Remove
Bolts (22),washers(23),damper(24),wash
ers(26

、

27) and nuts(28), Remove bolts

and nuts, securing fuel tank (25) to chassis
mounting brackets.Remove fuel tank (25).

Fuel tank assembly

Numbers in parentheses refer to Fig.2.
1.Remove the cover (15) and bolt securing
air cleaner (2) to fuel tank. Check condition of
gasket and replace if required.
2. Remove bolt securing level gauge (3) to fuel
tank (14) and remove level gauge (3). Check
condition of washer on level gauge (3) and
replace if required.
3. Remove bolts (7), washers (6), cover
plate(5) and O-ring (4) from fuel tank (14).
Discard O-ring (4).
4. Remove bolts (11), washers (10), cover
plate(9) and O-ring (8) from fuel tank (14),
discard O-ring (8).

Cleaning

Numbers in parentheses refer to Fig.2.
1. Remove all dirt particles from fuel strainer
and clean fuel strainer with clean diesel fuel.
2. Cover plate (9) port in fuel tank (14) can
be used as an opening to remove dirt and
sludge from the bottom of fuel tank (14) with
a clean dry cloth. Remove drain plug (12) and
fush fuel tank (14) with clean diesel fuel to
remove any remaining dirt particles. Reinstall
drain plug(12) and tighten securely.

Assembly

Numbers in parentheses refer to Fig.2
1.  Install  O-ring (4)  in groove of  fuel  tank
(14) boss and secure cover plate (5)  with
washers (6) and bolts (7).
2. Install  O-ring (8)  in groove of  fuel  tank (14)
boss and secure cover plate (9) with washers

Fig.2 Fuel tank assembly disassembly

1.Plug

9.Cover plate

2.Air cleaner 10.Washer

3.Level gauge 11.Bolt

4.O-ring

12.Drain plug

5.Cover plate 13.Screw plug

6.Washer

14.Fuel tank
welding assembly

7.Bolt
8.O-ring

15.Cover

Fuel Tank And Mounting

(10) and bolts (11),and secure plug (12).
3. Ensure gasket is located on level gauge (3)
and position  level gauge (3) in  fuel  tank  (14).
Secure level gauge (3) with bolt.
4.  Install  fuel  strainer  in  fuel  tank  (14).  If
removed install new gaskets in filter cap and
install filter cap assembly loosely to prevent
entry of dirt.
5.  Ensure  that  drain  plug  and  bolts  are
securely tightened in fuel tank.

Installation

See Fig.1 for the numbers in brackets, unless

otherwise specified.

WARNING

To prevent personal injury and property

damage, be sure lifting equipment is

properly secured and of adequate capacity

to do the job safely.

Note

: Tighten all fasteners to standard

torques listed in 'Tightening Moment Technical
Conditions of Standard Bolt and Nut' in 36.2.
Numbers in parentheses refer to Fig.1, unless

otherwise specified.

1.Using suitable lifting equipment, position fuel
tank (25) on the chassis mounting brackets
and Secure with damper (24), washers (23),
nuts(28), washers (26

、

27) and bolts (22).

2. Install articulating bolt(4), connector(7),
washers(5,8)and articulating body(6)to primary
Filter  (11). Secure Primary Filter  (11) to frame
with bolt(9)and washer(10).
3.  Connect  fuel  supply  lines(3)between
articulating body (6) and Connector (1), secure
with clamps(2).
4.  Connect  fuel  supply  lines  (16)  between
articulating  body  (6)  and  Connector  (17),
secure with clamps (2).
5. Connect fuel return lines(15) between fuel
tank (25) and Connector (13), secure with

Fuel Tank And Mounting

clamps(14).
6. Remove fller cap assembly from fller neck

on fuel tank (25) and fill fuel tank (25) with fuel
specified in Section 36.1, LUBRICATION
SYSTEM. Ensure vent hole in fller cap is clear
and install filler cap assembly on filler neck.
Tighten fller cap securely.
7. Open fuel shut off valve at the fuel filters.

8. Start the engine and run for a few minutes
to ensure fuel is being supplied to the engine.
Check for leaks at fuel lines and tighten if
required.
9. Remove body safety pins and lower the
body. Remove wheel chocks from all road
wheels.

Maintenance

Numbers in parentheses refer to Fig.1, unless

otherwise specified.

Prior to starting the vehicle check the fuel

level. Fuel tank should be filled at the end

of each shift to prevent condensation from

gathering in the tank.Ensure vent hole in fller

cap is clear to prevent a vacuum from building
up in fuel tank. Check condition of all fuel lines.

When filling fuel tank check that there is

no buildup of dirt and sludge at fuel strainer.

Remove and clean fuel strainer and fller cap

as  required. From  time  to  time make a
visual check on  the electrical  connections at
fuel level sender.The condition of fuel tank (25)
mounting should be checked carefully. Check
washers  (23) and dampers  (24)  for any sign
of wear or damage and repair or replace as
required. Check  that nut  (28), washer(26

、

27) and bolt (22) are securely tightened and
that no wear on mounting holes is evident.
tighten nuts and bolts as required.

Primary filter separator maintenance

Daily maintenance: Loosen the drainage at the
bottom of catchment cup, empty the collected
water.
Maintain the primary Filter separator every

Fuel Tank And Mounting

19000km or 500 hours, or the engine power is

insufficient.

1. Remove the strainer and catchment with
special tools. Identify strainer and catchment
gasket.
2. Remove all dirt particles from strainer.
Replace the same model strainer if seriously
blocked.
3. Clean catchment and gasket with clean
diesel fuel. Check the gasket and replace if it
is damage.
4. After cleaning, ensure gasket is located on
catchment and position catchment in strainer.
5. Supply diesel fuel around the strainer
except the hole in middle.
6. Clean strainer and gasket with clean diesel
fuel. Check gasket and replace if required.
7. After cleaning, ensure gasket is located on
strainer and position strainer with special tool.

Fuel Tank And Mounting

13 STEERING PIPELINE AND

JOINT

13.1 Piston Pump

Overview

The steering pump is an axial piston variable-
displacement (adjustable) pump with the high-
pressure operating capability. It is installed on
the power take-off (PTO) of engine. It supplies
pressure oil for steering and brake system
and it could control of the output in any given
time for demand of system. The set value of
pressure compensator is 18MPa.
The steering pump rotates counterclockwise
in the view from the input shaft end of pump.

Caution

: Do not drive the pump in the reverse

direction. Otherwise, the pump will be seized.
The pump is mainly composed of: a pressure
compensator valve, a pump housing, a driving
shaft, a valve plate, a rotating assembly.
The variable-displacement unit includes the
mechanism which can adjust the angle of
swash plate. When the cylinder body assembly
and the driving shaft rotate, the swash plate
can control the stroke of each piston. The
valve block is also used as the rear end cover
of the whole component and includes the oil
inlet and outlet; the bearing on the valve block
and the one on the pump body are utilized to
support the driving shaft.

Operating principle

Fig.13.1-2 is the operating hydraulic schematic
diagram of steering pump. The driving shaft
of rotating pump can rotate the cylinder body,
retainer plate and piston. The piston shoe
abuts the swash plate through retainer plate.
The angle of swash plate surface can cause
the repeated movement of each piston in the
cylinder body. The input and output ports are
connected to the slotted hole of port plate.
When the piston moves towards the outside
of cylinder body, vacuum is generated. The
oil is pressed into the cavity under the action

Fig.13.1-1 Piston pump

Fig.13.1-2 Operating schematic diagram of
steering pump

Steering Pipeline And Joint

of atmospheric pressure. The oil flows in the
cylinder  body,  passes  through  the  oil  inlet
slotted hole of port plate and reaches the oil
outlet slotted hole of port plate. When the
piston moves in the reverse direction, oil is
forced out of the cylinder body and enters into
the oil discharge outlet.
The  oil  liquid  flows  from  the  oil  discharge
outlet to the steering valve group and provides
the pressure to the steering oil circuit. The
pressure oil is split to the brake valve group
via the port 'G1' of steering valve group and
provides the pressure to the brake control oil
circuit.
The  internal  discharge  of  pump  returns  to
the oil tank through the oil drainage pipe of
steering pump.

Variable displacement

The  displacement  can  be  changed  by
changing  the  included  angle  between  the
return plate and the driving shaft. During the
period when the operating load of pump or the
pressure of system is continuously fed back
to the slide valve cavity of differential piston
and pressure-compensated valve, when the
pressure of system reaches the spring setting
value  of  pressure-compensated  valve,  the
valve  spool  moves  and  the  oil  flow  to  the
control slide valve is metered.
When the force generated by the control slide
valve overcomes the spring force of differential
piston,  the  angle  of  return  plate  will  move
to the minimum displacement position. The
angular displacement of return plate (i. E. the
change in the displacement) depends on the

desired flow and pressure of system.

When the displacement meets the system
requirement, the balance will be established
again.

Steering Pipeline And Joint

13.2 Cushion Valve Block

Overview

Cushion valve block is installed to the fixing
support under cab.
It is situated in the steering pipeline of Steering
control unit and steering cylinder. There are
four ports in total. Ports 'A', 'B' are connected
to the steering control unit. Ports 'A1', 'B1' are
connected to the cylinder.

Operating principle

See Fig.13.2-2 for schematic diagram.
Port 'A' is connected to port 'A1'. When the
pressure is larger than 20.7MPa (3000 psi),

some hydraulic oil will flow back to the oil tank
through relief valve or flow back to port 'B' and

'B1', so as to buffer the braking.

Disassembly

1. Park the truck at a horizontal working place
and apply the parking brake. Shut down the
engine.
2. Rotate the steering wheel in two directions
for several times to release the pressure of
steering system and accumulator. Chock all
wheels and set the main switch of accumulator
into the 'off' position.
3. Clean the cushion valve block and the
surrounding area, mark the hydraulic pipeline
mounted to each port of such valve.
4. Remove all the hydraulic pipelines from
the cushion valve block, drain the oil into a
proper vessel, cover all the hydraulic pipelines
and cushion valve block ports to prevent the
ingress of dust.
5. Remove the cushion valve block from truck,
use proper solvent to clean the surface of
cushion valve block, and then move to a clean
area for disassembly.

Installation

Note

: Tighten the hydraulic pipeline equipped

with the O-ring end face seal and replace the
'O'ring.

Fig.13.2-1 Cushion valve block

Fig.2 Hydraulic principle of cushion valve block

Steering Pipeline And Joint

WARNING

The pressure is dangerous. Before the

operation, the steering wheel should be

rotated back and forth for several times

to release the pressure in the system. If

the pressure is not released, it will lead to

personal injury and property loss.

To prevent personal injury and property

loss, ensure that the wheels are chocked

well and the chock and the hoist device

have sufficient capability and can work

safely.

1. Install the cushion valve block onto its fixing

support. Use the fasteners removed during

disassembly to fix it.

2. According to the signs made during
disassembly, connect all oil pipes to the
cushion valve block and fasten them.
3. According to the stipulations in the ‘Hydraulic
Oil Tank Assembly’, check the oil level of oil

tank. Refill oil to the proper oil level according

to the stipulations.
4. Remove the chock, set the main switch
of accumulator into the 'on' position, start up
the engine and operate the steering system.
Check the steering system for leakage. If
necessary, tighten the connecting piece and
recheck the oil level.

Maintenance

The maintenance of cushion valve block is
only limited to the replaceable part.

Special tools

No special tool is required in steps described
in this chapter. These tools can be purchased
from the agents.

Steering Pipeline And Joint

13.3 Oil Filter

Overview

The oil filter is installed inside the left
longitudinal beam and under the left and
right longitudinal beams under the frame. It is
located in the steering pipeline between the
steering valve group and the steering pump
and in the pipeline connecting the cooling
system to the rear brake.

Operation principle

The hydraulic oil from the piston pump enters
to filter, flows into the annular region of filter
bowl and reaches the exit through filter.
The pressure of filter drops to the minimum
during filter cleaning. When the hydraulic oil

passes through the oil filter, the dirt in the oil is
deposited on the filter. The more the dirt is, the
higher the pressure drop of filter becomes, so
must change filter at once..

Maintenance

Replace for every 1,000 hours of operation.

Replacing the filter

Note

: Tighten all hydraulic pipelines equipped

with the O-ring end face seal joint and replace
the 'O'ring.

WARNING

Pressure is dangerous. Rotate the steering

wheel in each direction and release the

system pressure. If the pressure is not

released according to the stipulation, it will

lead to personal injury and property loss.

To prevent personal injury and property

loss, ensure that the wheels are chocked

well and the chock and the hoist device

have sufficient capability and can work

safely.

1. Place the truck in a flat working area, apply

Steering Pipeline And Joint

Fig.1

Oil Filter

Diagram

1.Screw 2.washer 3.Pressure Oil Filter

Hoist Pipeline And Joint

14 HOSIT PIPELINE AND

JOINT

14.1 Hoist Pump

Overview

The hoist pump is a gear pump installed to
engine PTO. It supplies oil to hoist system
independently.

Operation

See Fig.14.1-2 for the principle of hoist pump.
When the drive gear rotates, the driven gear
rotates in the reverse direction. The tooth
socket between the teeth of gear will bring the
hydraulic oil from the gear pump case inlet
to the outlet. When the teeth of gears are
engaged again, the hydraulic is forced out of
the outlet. The delivery capacity of hoist pump
is determined by the width of its corresponding
gear set and the rotating speed of drive gear.
The hoist pump delivers oil to hoist control
valve. According to the movement of valve
spool, the oil flows to body hoist circuit, or
if the valve spool is at 'float' position, the oil

flows through the confluence block behind the

hoist control valve to supply the disc brake
cooling system.

Fig.14.1-1 Hoist pump outside diagram

Fig.14.1-2 Hydraulic schematic diagram of
hoist pump

14.2 Hoist Valve

Overview

See Fig.14.2-1 for the numbers in brackets.
The hoist valve is installed inside the
longitudinal beam of left frame. It is used to
guide the hydraulic oil to the hoist cylinder for
hoist or lowering the body. Depending on the
position of valve spool, the oil for disc brake

cooling system is supplied via the confluence

block.
The hydraulic oil is pumped into hoist valve (1)
by the double-gear pump installed to engine
PTO. The hoist valve consists of one three-
position valve spool and relief valve. It is
fastened to the inside of left longitudinal beam
by screw (2). The three positions of valve

spool are: 'hoist', 'maintaining and floating' and

'lowering' (with power lowering). The valve

spool kept at 'maintaining and floating' position

will  compress  the  internal  and  external
springs, which will change the valve spool
to 'maintaining' position from 'hoist' position.
The action of valve spool is controlled by the
pilot pressurized oil provided by the pilot oil
source valve group. When the hoist handle
valve on the control board on the right of seat
is operated by the operator, the pilot oil source
valve  group  will  provide  3.5MPa  (507psi)
pressure to actuate the action of hoist valve
spool.
The  relief  valve  assembly  is  installed  to
port 'P/P1'. If the pressure exceeds 18MPa
(2610psi), the relief valve will open to allow
the oil to return to the tank. The relief pressure
can be measured at the pressure check port
'G' behind the tank.

Operation

Body at 'maintaining and floating' position

See Fig.14.2-2 for the hydraulic schematic
diagram of hoist valve operating in the

'maintaining and floating' position.

When the hoist lever valve and valve spool

Fig.14.2-1 Assembly drawing of hoist valve

1. Hoist valve

2. Screw

Fig.14.2-2 Hydraulic schematic diagram of
hoist valve

Hoist Pipeline And Joint

are kept at 'maintaining and floating' position,

i. E., the valve spool is kept at the neutral
position, the oil will enter port 'P/P1' of control
valve block, flow through the valve and flow
out of port 'T', enter the confluence block of
disc brake cooling system and supply the
disc brake cooling system. The valve spool
obstructs oil from entering and leaving the
body hoist cylinder and keeps the piston of
cylinder body at the original position.

Body at the 'hoist' position

See Fig.14.2-2 for the hydraulic schematic
diagram of hoist valve operating in the 'hoist'
position.
When the hoist control handle is moved to
'hoist' position, i. E., the valve spool is at the
hoist position, the hydraulic oil will enter port
'P/P1' of control valve block. The pilot oil
pressure opens the valve spool for the oil to
flow through the valve spool, port 'B', 'hoist
port' and enter the hoist cylinder. The returned
oil from the hoist cylinder returns to the hoist
and disc brake cooling oil tank through port 'A'
of balanced valve, port 'A' of hoist valve, valve
spool passageway and port 'T1'.

Body at the 'lowering' (power lowering)

position

See Fig.14.2-2 for the hydraulic schematic
diagram of hoist valve operating in the
'lowering' position.
When moving the hoist control handle to the
'lowering' position, the valve spool in valve
block will be located at the right position shown
on Fig.2, through which the hydraulic oil can
enter port 'P/P1' of control valve block. The
pilot oil pressure opens the valve spool for oil
to reach the balanced valve group through the
open passageway of valve spool and port 'B'.

The oil liquid flows through the balanced valve

and reaches the 'forced landing port' of hoist
cylinder. The returned oil from hoist cylinder
of body enters port 'B' of control valve block,

Hoist Pipeline And Joint

14.3 Balanced Valve Group

Overview

The balanced valve group is installed on the
support behind the transmission. The balanced
valve group in the hydraulic hoist system can
be used to prevent the formation of vacuum in
the hoist cylinder due to the imbalanced body
during unloading. In addition, it also used to
leading oil back to the tank of hoist and brake
system via the way of the hoist control valve.

Operation

See Fig.14.3-2. When hoist the body, the
returned oil in the hoist cylinder enters the
balanced valve group from ports 'A1', 'A2'.
When lowering the body with control valve,
the pressurized oil will be delivered to ports
'A1', 'A2' of the balanced valve. The spool

will moves and pressure oil flow out of part A

to lower the body down at the pressure is 17
Mpa ( 2465 psi ). return oil goes through hoist
valve back to thank of hoist, brake and cooling
system.

Disassembly

1. Ensure that the body is completely lowered,
or fix the body with the safety pin when the
body is in the hoist position. Apply the parking
brake, shut down the engine and chock all
wheels properly.
2. Use a proper solvent to clean the balanced
valve group and make a sign on the hydraulic
rubber hose to facilitate correct installation.
3.  Remove  the  hydraulic  pipe  from  the
balanced valve and drain the oil into a proper
container.  To prevent ingress of dirt, cover all
pipe openings and each port of the balanced
valve group.
4.  Remove  the  fasteners  which  fix  the
balanced valve onto the support. Take down
the balanced valve and place it in a clean
working area to facilitate disassembly.

Port “A” of lifting valve

Port “B” of lifting valve

Forced landing port of lifting valve Lifting port of lifting valve

Fig.14.3-1 Assembly drawing of balanced
valve group

Fig.14.3-2 Schematic diagram of balanced
valve

Hoist Pipeline And Joint

SANY SRT95C Off-Highway Truck. Service Manual - page 21