SANY SRT95C Off-Highway Truck. Service Manual

valve and put open end of the hose into a
clean container.
3. Press down the brake pedal, and gradually
unscrew the bleeder valve (14), which should
be kept open until the oil exhausting from the
bleeder valve is free from bubbles. Then screw
the bleeder valve, release the brake pedal
and remove the bleeder hose.

Caution

: This system is equipped with the

accumulator which can still maintain system
pressure even when engine is shut down. If
system pressure is zero, it will be required to
start the engine before bleeding to pressurize
the system. Engine should be shut down
before bleeding procedure is performed.

warning

This brake system operates at high

pressure. The bleeder valve should be

loosened carefully.

4. Repeat Steps 1 - 3 on each brake head
assembly.

Maintenance

Every 10 hours of operation(Daily)

Inspect the brake assembly, ensure that all
connecting bolts are tightened and there is no
leakage. Inspect the boot for demage.
Refer to Chapter 15 'Hydraulic Oil Tank
Assembly', and check the oil level. If the oil
level is low, then add oil. The oil selected

should meet the specifications recommended

i n S e c t i o n 3 6 . 1 ‘ L U B R I C AT I O N A N D
MAINTENANCE’.

Front Axle Assembly

Special tools

Refer to Section 38.3'Service Tools'.

Special torque specifications

Fig. No.

No.

Description

Torque

N·m

2-4

Bolt

1500~1550

2-4

Bolt

2250~2300

2-4

Bolt

1300~1360

2-5

Bolt

180~200

2-5

Bolt

1000~1050

Front Axle Assembly

2.1.3 Steering arm assembly

Disassembly

Numbers in parentheses refer to Fig.2-6.
1. Remove screw (4).
2. Remove key (3) from keyway of steering
arm welding body (1).
3. Check wear condition of lower end pin(2),
if change needed, partly heating steering arm
welding body (1), remove lower end pin (2).
4. Place disassembled parts in a clean work
for assembly.

Assembly

Numbers in parentheses refer to Fig.2-6.
1. If change needed, partly heating steering
arm, assembly lower end pin (2), keeping
keyway aligned of lower end pin (2) with that
of steering arm.

Fig.2-6 Left steering arm assembly

1. Steering arm welding body 2.Lower end pin

3. Key

4. Screw

Front Axle Assembly

2. Place key (3) into keyway of steering arm
welding body (1), keeping mounting holes of
key aligned with those of keyway.
3. Fasten key (3) with screw (4) , complete
assembly of steering arm assembly.

2.1.4 Front suspension cylinder

Fig.1 Sectional view of front suspension cylinder

Front Axle Assembly

4 5

14 15

F r o n t s u s p e n s i o n s y s t e m – F r o n t

suspension cylinder

overview

Numbers in parentheses refer to Fig.1.
The front suspension cylinder is mounted on
frame to support the front wheel and absorbs
road shock as the wheel travels over rough
and uneven surfaces. Oil and compressed

nitrogen fill the inside of cylinder tube.

The cylinder contains piston rod (6), guide
sleeve(13),cylinder tube(25) and piston (23).
Oil and compressed nitrogen fill the inside
of the cylinder. When the wheel hits a bump
on the ground, piston rod(6) is forced inward
in the cylinder. The pressurized nitrogen
compresses against the oil inside the cylinder.
As the nitrogen pressure builds up in the
cylinder, piston rod (6) slows down until it
stops. Nitrogen pressure causes piston rod
(6) to extend back to its original position. As
piston rod (6) is compressing, ball (7) is forced
off its seat, allowing the increased pressure to
fill the cavity between tube cylinder tube(25)
and piston rod (6) faster. As piston rod (6)
returns to the normal position, the pressure
in the cavity forces ball (7) against its seat.
Pressure in the cavity is forced to return only
through passage in the piston rod thereby
slowing and smoothing the return travel of the
piston rod(6).

1.Snap ring

10.Bolt

19.Seal

2.Bearing

11.Plate

20.Buffer seal

3.Oil fitting

12.Bolt

21.Wear ring

4.Plug

13.Guide sleeve

22.Wear ring

5.Charge valve

14.Retainer ring

23.Piston

6.Piston rod

15.O-ring

24.Bolt

7.Ball

16.Retainer ring

25.Cylinder tube assy.

8.Clamp

17.Seal-wiper

26.Plug

9.Dust boot

18.Backup ring

27.Buffer stopper

Front Axle Assembly

warning

Pressurized cylinders. Release pressure

as described under 'Relieving Cylinder

Pressure'before removing valves or

fittings. Accidental release of pressure

will result in personal injury and property

damage.

To prevent personal injuries and property

losses, be sure that the air pressure in the

cylinder is completely released before the

suspension is dismantled. In addition, be

sure blocking and lifting equipment is of

sufficient capacity and properly secured to

do the job safely.

Removal

Numbers in parentheses refer to Fig.2&3&4.
1.Position the truck in a level work area, apply
the parking brake and switch off the engine.
2.Turn the steering wheel in both directions
several  times  to  relieve  pressure  in  the
steering system. Block all road wheels.
3.Relieve nitrogen pressure from both front
suspension  cylinders.  Refer  to  “Relieving
Cylinder Pressure”, in this section.
4.Jack frame up at “horse collar” until front
suspension cylinder is fully extended.
5.Jack up front suspension cylinder until tyre is
off ground and block steering arm in position.
6.Remove  front  tyre  and  rim.  Refer  to
Chapter1 'FRONT WHEEL ASSEMBLY'.
7. Remove pins attaching tie rod and steering
cylinder to steering arm.Secure both tie rod
and  steering  cylinder  away  from  the  work
area.  Refer  to  Section  2.2,  "STEERING
MECHANISM".
8.Position lift truck forks under front suspension
cylinder and block up front suspension cylinder
as shown in Fig.3.
9.Remove pin assembly (1, 2, 4,Fig.2) which
securing front suspension cylinder.

Fig.2 Front suspension cylinder mounting

1. Pin
2. pin
3. A-arm
4. Pin
5. Front suspension cylinder

Fig.3 Disassembly and installation of front
suspension

1. Front suspension cylinder
2. Wooden blocking
3. Lift truck forks

Front Axle Assembly

1. Bolt

6. A-arm

plate

7. Bolt

3. Bolt

8. Steering arm assembly

plate

9. Front suspension cylinder

5. Bearing

10.Carefully remove the front suspension
cylinder(5, Fig.2), A arm(3, Fig.2),and steering
arm(8, Fig.4)to a suitable work area for further
disassembly.
11. Follow procedures in Steps 4 through 10
above if the other front suspension cylinder is
to be removed.

Disassembly

Numbers in parentheses refer to Fig.4.

warning

To prevent personal injury and property

l o s s , b e s u r e b l o c k i n g a n d l i f t i n g

equipment is of sufficient capacity and

properly secured to do the job safely

1. Remove A-arm.
a. Remove the bolt (1, Fig.4) and plate (2,
Fig.4).
b. Remove the A-arm (6, Fig.4).
c. Remove the bolt (3, Fig.4) and plate (4,
Fig.4) to separate the A-arm(6, Fig.4) and
bearing(5, Fig.4).
2. Remove steering arm.
After  the A-arm  is  removed,  remove  eight
bolts(7, Fig.4) to separate the steering arm
(8, Fig.4) from suspension cylinder (9, Fig.4).
Remove flat key in keyway of the steering
arm.
3. Remove front wheel
R e f e r   t o   C h a p t e r   1   “ F R O N T  W H E E L
ASSEMBLY” for the removal of front wheels.
4 Remove the front suspension cylinder
Numbers in parentheses refer to Fig.5.
a.Remove clamp(8),bolts(10) and plate(11)
securing dust boot(9) to piston rod (6) and
guide sleeve(13), then remove dust boot(9).
b.Remove charge valve (5) and plug(4) from
piston  rod(6).  Drain  oil  from  suspension
cylinder into a suitable container. Remove

Fig.4 Remove A-arm and steering arm

Front Axle Assembly

bolts (12) securing guide sleeve (13) on
cylinder tube (25).
c.Securing the suspension cylinder in a proper
position for disassembly.
d.Install a lifting eye in the top of piston rod
(6) and attach to an adequate lifting device.
Slide piston rod (6), piston (23 ) and guide
sleeve(13) as an assembly out from top of
cylinder tube (25). Be careful not to damage
the surface of any component.
e.Remove bolts (24) securing piston (23)
to piston rod (6). Knock on the piston (23)
assembly with a soft hammer to remove it from
the end of piston rod (6).Remove wear ring (22)
from the piston (13).
f.Take out the ball (7) from the hole of piston
rod (6).
g.

Note

: Take care not to misplace ball (7).

h.Carefully fix piston rod on the base of press

machine and make the hole in the rod
end downwards. Separate piston rod (6) from
the guide sleeve (13). Be careful not to
damage the surface of components.
i.Remove and discard retainer rings(14) and
O-rings(15) from the outer groove of guide
sleeve(13). Then remove and discard snap
ring(15), seal-wiper (17),backup ring (18),
seal(19) ,buffer seal(20) and wear ring(21)
from the inner groove of guide sleeve (13).
j.Remove buffer stopper (27) from the guide
sleeve(13).

Front Axle Assembly

Fig.5 Disassembly and assembly drawing of front suspension cylinder

1.Snap ring

10.Bolt

19.Seal

2.Bearing

11.Plate

20.Buffer seal

3.Oil fitting

12.Bolt

21.Wear ring

4.Plug

13.Guide sleeve

22.Wear ring

5.Charge valve

14.Retainer ring

23.Piston

6.Piston rod

15.O-ring

24.Bolt

7.Ball

16.Retainer ring

25.Cylinder tube assy.

8.Clamp

17.Seal-wiper

26.Plug

9.Dust boot

18.Backup ring

27.Buffer stopper

Front Axle Assembly

Inspection and maintenance

Numbers in parentheses refer to Fig.5.
1.Wash all parts thoroughly in a suitable
solvent. Dry all parts with compressed air.
Check all inner and outer grooves in guide
sleeve(13) and piston(23) for cleanliness.
2.Inspect cylinder tube (25), piston rod (6) ,
piston (23) and guide sleeve(13) for scores,

scuffing or small ridges in the walls. Use a fine

stone to smooth out any defective areas. If
damage is too extensive, replace with a new

Front Axle Assembly

part.
3.Inspect all cylinder assembly components
for signs of unusual distortion or excessive
wear. Replace defective components.
4.Inspect plug (4

，

26), Charge valve (5). If the

seal or part is damaged, replace with a new
part. Inspect steel ball(7). If they are damaged,
replace them in time.
5.Check the seating positions in piston rod(6)
and cylinder tube (25). If threads in any of
these parts are damaged, restore the threads.
Replace defective parts if necessary.
6.Inspect the holes of frame for abnormal
distortion or damage. They must be repaired
before the pin are installed.
7.Inspect wear ring (21

，

22) and bearing for

excessive wear or damage. Replace them if is
damaged.
Note: The maintenance standard of bearing
(2), wear ring (21,22), buffer stopper(27) refer
to Fig. 1. and Tab.1.

Tab.1 Maintenance standard

No.

Check item

Criteria

Remedy

Clearance
between race
and ball of
bearing

Standard

size

Tolerance

Standard

clearance

Clearance limit

Replace wear
ring

Shaft

Hole

115

0.085- 0.165

0.69

Clearance
between
piston rod
and wear
ring

200

-0.043
-0.106

+0.272

0.043-0.368

0.4

Clearance
between
cylinder and
wear ring

250

-0.05

-0.296

+0.072

0.05-0.368

0.8

Replace wear
ring

Deformation
of buffer
stopper

Measuring method:
Measure protrusion and elongation of stopper.

Protrution

Elongation

Tube

Guide

sleeve

Buffer

stopper

Rod

Elongation :
Max.5mm
Protrusion:
Min.15mm
No cracks

Replace

Assembly

Numbers in parentheses refer to Fig.5.

Note

:Apply a light coating of clean hydraulic

oil to all components as they are assembled.
This facilitates the assembly procedure. Make
sure that all work is done in a clean area so
that no contaminants can get into the oil.
1.Install new snap ring (16), seal-wiper(17),
backup ring(18),seal (19) ,buffer seal(20)and
wear ring (21) into the corresponding groove
in the inner bore of guide sleeve (13). Before
seal-wiper is installed, waterproof glue should
be applied onto the external surface of frame.
2.Install new retainer rings (14)

，

O-rings (15)

and buffer stopper(27) into the corresponding
groove on the external surface of guide sleeve
(13).
3.Use a proper seal ring expander or similar
tool to prevent the seal ring from damage.
Carefully install the guide sleeve (13) into
the piston rod (6). The large end should be
installed at first and sufficient space should
be provided to install the piston (23) into the
piston rod. Be careful not to damage seal.
Then install balls (7) into the corresponding
hole of piston rod (6).

Note

: Fix these balls temporarily with a little

clean grease in the rest assembly procedure.
4.Install new wear ring (22) into the
corresponding hole of piston (23). Install
piston assembly to piston rod (6). Slide piston
assembly up piston rod (6) enough. Secure
piston (23) assembly to piston rod (6) with

Front Axle Assembly

bolts (24). Tighten bolts to torque of 136 N•m.

5.Install a lifting eye in the top of piston rod
(6) and attach to an adequate lifting device.
Insert  piston rod (6) , piston (23) and guide
sleeve(13)  as  an  assembly  (refer  Fig.6)
through the top of cylinder tube assy.(25).
Pushing piston rod in until piston (23) bottoms
inside  the  cylinder  tube.  Be  careful  not  to
damage the surface of any component.

Note

: Because of close tolerances, care will

have to be taken when assembling piston rod
(6) and piston(23) assembly into cylinder tube
(25).
6.Secure guide sleeve (13) to cylinder tube
assy.(25) with bolts (12). Tighten bolts to

torque of 136 N•m.

7.Install dust boot(9) with clamp(8) , bolts(10)
and plate(11) to secure it to piston rod (6) and
guide sleeve(13).
8.Install charge valve (5) and plug(4,26) on
suspension cylinder. The tighten torque of
charge valve is 50Nm. The tighten torque

of inflation valve core is 0.35~0.45N•m, the

tighten torque of inflation valve protecting

cover is 4.5 ~5.5N•m. Before installation,

inspect the seal rings of inflation valve and
plug for signs of damage, replace them in time
if they are damaged.
9.Install bearing(2) and snap rings (1) to the
hole of piston rod(6).

Note

:the piston rod and piston assembly

should be installed into the cylinder tube
assembly with great care because the
tolerance is small.

Installation

Numbers in parentheses refer to Fig.2.
1.Clean  all  parts  surface  of  suspension
cylinder and frame to make them smooth.
2.Place  cushion  block  on  the  fork  of  fork
truck  as  shown  in  Fig.3. Then  locate  the
front  suspension  cylinder  assembly  in  the
installation  position  on  frame. The  weight
of  suspension  cylinder  is  over  765kg.  If  it

Fig.6 Piston rod component

1. Piston rod

2. Guide sleeve

3. Piston

Front Axle Assembly

is charged with oil or fluid in advance, the

volume of oil or fluid will be 23L.

3.Secure front suspension cylinder (5,Fig2) to
frame with pin assembly(1,2,3, Fig3).After pins
are installed, use bolts and washers to lock
them.
4.Move away the installation equipment.
5.Connect brake hydraulic pipeline to brake
calipers and exhaust the brake system. Refer
to Section 2.1.2 ‘FRONT BRAKE ASSEMBLY
AND INSTALLATION’.
6.Install front tyre and rim assembly as
described in Chapter 1 'FRONT WHEEL
ASSEMBLY'.
7.Repeat Steps 1-6 to install the suspension
cylinder if the suspension cylinder on the other
side is removed.
8.Charge the suspension cylinder according to
the 'charging instructions'.

warning

To prevent personal injury and property

l o s s , b e s u r e b l o c k i n g a n d l i f t i n g

equipment is of sufficient capacity and

properly secured to do the job safely.

Maintenance and adjustment

Periodic maintenance includes the following
steps:
1.Clean the device. Check the signs of wear,
damage or oil-gas leakage. Pay special
attention to the exposed part of piston rod

and inflation valve. Repair or replace them as

required.

Note

:The dust boot is equipped with zipper

which  can  be  replaced  without  remove
suspension cylinder or pin.
2.Check  all  parts  for  signs  of  wear  or
looseness. In case of any looseness, repair or
replace them if necessary.
3. Inspect the exterior of suspension cylinder
for  signs  of  oil  leakage.  Repair  or  replace

Front Axle Assembly

according to the requirements and add oil
again according to the method described in
the instructions.

Note

: Refer to following procedure in this part

for detailed instructions of oil level inspections.
4. Check the relevant operating conditions of
suspension cylinder according to the following
method:
1)Run the truck and make that two suspension
cylinder can achieve a balance at the normal
operating temperature.
2) Position the empty truck on a flat ground.
Measure the distance A between the center
of pin and the end cap of guide sleeve as
shown in Fig.8. The value obtained should
be  approximately  410mm(with  the  error
not exceeding 10mm; refer to Fig. 8). If the
distance  is  not  in  this  range,  check  and
adjust the nitrogen pressure according to the
procedure below this part. The following signs
indicate that it is necessary to maintain the
interior of suspension:
a.There  is  sign  of  oil  leakage  in  the
surrounding of suspension cylinder.
b. The gas column height changes frequently.
It is required to charge nitrogen.

Note 1

: The reduction in the gas column

height is usually accompanied by the loss of
gas.

Note 2

: At the circumstance of normal gas

column height, the offset of gas height
indicates that the oil is losing.

Note 3

: The traveling or excessive elasticity

of gas will lead to repeated operation of
suspension cylinder.
3) After the suspension cylinder is inflated
to the correct height, apply the rated load,
park the truck on a flat ground, the distance
A between the center of pin and the end cap
of guide sleeve should be equal to 320mm
or higher. (If A is less than 320mm, check the
truck is overloaded or not. If not, deflate and

add oil, inflate gas again ).

Note 4

: The unsmooth traveling or excessive

Front Axle Assembly

elasticity of gas column will lead to repeated
operation of suspension at its travel terminal.

Charging front suspension cylinder

warning

To prevent personal injuries and property

losses, ensure that the air pressure in the

cylinder is completely released before the

suspension is dismantled. In addition, be

sure blocking and lifting equipment is of

sufficient capacity and properly secured to

do the job safely.

Relieving Cylinder Pressure

warning

Pressurized cylinders. Release pressure

as described under 'Relieving Cylinder

Pressure' before removing valves or

fittings. Accidental release of pressure

will result in personal injury and property

damage.

Note

:Truck must be unload and on a level

surface prior to relieving suspension cylinder
pressure.
1. Support the frame near the suspension
cylinder with blocking and/or a hydraulic jack
with adequate capacity.
2. Remove the cap from nitrogen charging
valve at the top of the cylinder. Turn the hex
nut on the valve 1/4 to 1/2 turn counter-
clockwise and depress the valve core. If no
gas escapes, continue to turn the hex nut in
1/4 turn increments until the nitrogen releases
as the valve core is depressed.
3.Remove blocking or release pressure on the
hydraulic jack and allow the truck’s weight to
fully retract the suspension cylinder rod.
4.Depress nitrogen charging valve core again

Front Axle Assembly

to be sure all pressure has been relieved.

Note

:Nitrogen leaving the cylinder will often

carry oil with it. This results form foaming
of the oil in the cylinder. The foaming takes
place as nitrogen which was dissolved in the
oil at high pressure expands at atmospheric
pressure. The oil lost in this operation must be
replaced in the charging operation. The longer
the oil is allowed to stand at atmospheric
pressure after discharging cylinder, the easier
it will be to purge cylinder of bubbles in the oil
when recharging.

warning

Pressurized cylinders. Keep valve core

depressed until all gas is bled from

cylinder. Failure to release all pressure

may result in personal injury or property

damage.

Charging Instructions

Note1:

This procedure should be performed

after the suspension cylinder is installed
on mining truck. If it is not installed, the
suspension cylinder should be placed with a
proper supporting form and fastness before
this procedure is operated.

Note2:

To ensure that both suspension

cylinders  will  be  equally  charged  to  the
required  height  specifications  and  equal
pressures, both cylinders should be charged
simultaneously. Also when front suspension
cylinders  are  being  charged,  both  rear
suspension  cylinders  should  be  extended
equally. This can be accomplished by placing
equal  thickness  blocks  between  axle  and
frame at the bump stops. It may be necessary
to raise frame slightly to install spacers. Be
sure  to  remove  spacers  when  charging  is
complete.

Note3:

The pressure of a confined gas varies

directly with its temperature. Hence, extreme

Front Axle Assembly

SANY SRT95C Off-Highway Truck. Service Manual - page 5