SANY Crawler Hydraulic Excavator SY215CLC (CUMMINS QSB6.7 engine). Shop Manual

Disassembly and Assembly

SY215C

8-84

4. Pulling out the piston rod

★

Be sure to have removed the tubing
cover.

★

Prepare a suitable container to collect
oil coming out of the oil port.

★

After pulling out the piston rod to its
limit, slowly loosen the cylinder head
and pull it out.

★

Remove the piston rod (1) with the
cylinder head (2) and place them on a
wooden sleeper.

5. Fixing the piston rod

★

Use pin bore on the rod end or the

part of the ear to prevent turning of the
piston rod.

Sleeper

ZX215-1006166

Fixing

ZX215-1006167

Disassembly and Assembly

SY215C

8-85

7. Removal of piston assembly

Remove in turn the piston (7), buffer sleeve
(6) and cylinder head (2).

6. Remove of the piston nut (5)

1) Remove the fixing screw (3) from the

piston nut (5).

★

Around the fixing screw there are two
points that have been punched against
loosening. After removing the riveted
part with a hand drill, loosen and
remove the

xing screw (3).

2) Remove the steel ball (4).

3) Remove the piston nut (5).

★

The piston nut (5) is very tight. To
loosen the piston nut (5), prepare a
hydraulic jack or a spanner powered
by hydraulic cylinder. An extension rod
should be ready when removing the
piston nut (5) manually.

Drill bit

ZX215-1006168

Hydraulic jack

Hydraulic cylinder

ZX215-1006169

ZX215-1006170

Disassembly and Assembly

SY215C

8-86

8. Removal of the buffer sleeve (8) on the

bottom end

1) Remove

rst the piston nut (5).

2) Use a tool like rubber hammer to tap

the piston nut (5) slightly for removal
while keeping the piston rod and the
buffer sleeve (8) intact. Remove the
elastic ring (9).

3) Slide the buffer sleeve (8) toward the

piston threads in order to remove the
two-piece stopper ring.

4) Remove the buffer sleeve (8).

5) There is an opening in the buffer seal

(10). Take advantage of this opening to
remove the buffer seal (10).

9. Removal of piston seal

1) The slide ring (12) and the guard

ring (13) can be simply removed with
hands.

2) The seal (14) can be removed with a

hammer and a

at-head screwdriver.

3) Remove the O-ring seal (15) with a pry

bar.

★

The removed seals should not be
reused.

10. Removal of buffer ring (16)

★

The buffer ring (16) is installed in the
inner groove in the cylinder head. Use
a tool with sharp end to pry it out and
remove it with a scraper.

Thread

Piston rod

one gap

(2 pcs)

ZX215-1006171

Bench clamp

Piston

Screwdriver

ZX215-1006172

ZX215-1006173

Disassembly and Assembly

SY215C

8-87

11. Removal of the U-ring (17) and the dust

ring (18)

1) Remove the U-ring (17) with a tool such

as screwdriver.

2) Pierce a tool (such as a screwdriver)

into the dust ring (18) and hammer the
screwdriver to remove the dust ring
(18).

★

The removed seals should not be
reused.

12. Removal of bushing (19)

1) Remove the elastic ring (20) from the

cylinder head (2) with a screwdriver.

2) Push the bushing (19) out with the help

of clamps and press.

13. Removal of bushing (21)

1) Remove the dust ring (22) on the side

of cylinder barrel and piston rod with a
tool such as screwdriver.

2) Remove the bushing (21) with the help

of a suitable cushion block.

Press

Cushion

Support

ZX215-1006174

Disassembly and Assembly

SY215C

8-88

8.22.2 Assembly

1. Installation of bushing (21)

1) Use a mounting tool to press the bush-

ing (21) into the bushing (lubricated
with hydraulic oil) on the side of piston
rod and cylinder barrel.

2) Install the dust ring (22) with the help of

a suitable cushion block.

2. Assembly of cylinder head (2)

1) Use the press to push in the bushing

(19).

★

Apply hydraulic oil to the inside of
cylinder head in advance. Make sure
that the bushing (19) pushed in is free
from a raised shoulder.

2) Use the press to push in dust ring (18).

3) Install the guard ring and the U-ring (17)

sequentially in the U-groove.

★

Install the U-ring (17) in correct direc-
tion. Make sure that the U-ring is intact
before installation.

★

Inverse installation will cause leak of
oil.

★

Make sure that the U-ring is free from
any corrugation or permanent deforma-
tion after installation.

Piston rod

Cushion

Press

Mounting tool

ZX215-1006175

Surface
under pressure

Hydraulic press

Tool

ZX215-1006176

Press in

Tool

U-groove

ZX215-1006177

Disassembly and Assembly

SY215C

8-89

4) Installation of buffer ring (16)

★

Make sure that the seal is installed in
correct direction. Inverse installation
can cause high pressure between the
buffer ring (16) and the U-ring (17),
which may lead to deformation or
breakage of oil cylinder.

5) Install the elastic ring (20) to prevent

the fall of the bushing (19).

3. Assembling the piston assembly

1) Installation of seal (14).

★

Install

rst the O-ring seal and the one-

side guard ring (13) on the piston.
Place the piston on the press. As
shown in the illustration on the right,
the seal (14) is installed with the tools
indicated.

2) Correction of seal (14)

★

Install the seal (14) and the guard
ring (13) on the other side. In order to
prevent the expansion of the seal (14),
a corrector must be used to correct the
seal (14) which has been stretched
during installation. The piston rod may
not be able to go in the cylinder barrel if
the seal (14) is not corrected timely.

3) Installation of slide ring (12)

★

Slightly open the slide ring (12) and
install it axially. Excessive opening of
the slide ring (12) can fail installation.

ZX215-1006178

Press

Tool

Block

Press

Corrector

Piston

Tool

O-ring

ZX215-1006179

Disassembly and Assembly

SY215C

8-90

4. Assembling the piston rod assembly

1) Fix the piston rod (1).

2) Install the cylinder (2) on the piston rod.

★

Make sure that the dust ring lip or the
U-ring lip is not stopped by the shoulder
of any part. Install the cylinder head
and the piston rod with the tools.

3) If the bottom side of cylinder contains

a buffer (not for bucket cylinder), install
the buffer bearing and the buffer seal in
the following order.

i) Let the notched side of the buffer

seal (10) face the piston while in-
stalling the buffer seal (10) in the
groove.

ii) Install the buffer sleeve (8) accord-

ing to the indication in the illustra-
tion on the right.

iii) Install the stopper ring in the

groove. Install the elastic ring af-
ter the buffer sleeve (8) is pushed
to the bottom. A rubber hammer
should be used for the tapping job
in order to avoid damaging the pis-
ton rod and the buffer bearing.

Assembly tool

ZX215-1006180

Gap facing thread direction

Thread

Piston rod

One gap

(2 pcs)

Head end buffer

ZX215-1006181

Disassembly and Assembly

SY215C

8-91

Gap facing piston side

Rod end buffer

ZX215-1006182

4) If the head side of cylinder contains a

buffer, install the buffer sleeve (6) and
the buffer seal (23) according to the fol-
lowing order.

i) The piston nut must be installed af-

ter installation of the buffer bearing.

ii) The buffer seal (23) must be in-

stalled in the groove, with its notch-
es facing the piston.

iii) The buffer sleeve (6) must be in-

stalled according to the illustration
on the right.

5) Tighten the piston nut (5).

Piston nut (arm):

9600 N·m {979.6 kgf·m}

Piston nut (boom and bucket):

6200 N·m {632.6 kgf·m}

★

Insufficient tightening can cause oil
leakage, loose nut and thread break-
age. In addition, excessive tightening
can cause expansion of the buffer shaft
on the extending side or deformation of
piston on the contact side.

★

Thoroughly clean and grease (with
banana oil) the threaded portions of
the piston, nuts and piston rod before
tightening the nuts.

6) Treatment of the piston against loosen-

ing

Disassembly and Assembly

SY215C

8-92

★

After the piston nut (5) is tightened,
put in the steel ball (4), tighten the
setscrew (3) and punch to rivet the two
peripheral points.

Setscrew (3):

66.9 N·m {6.8 kgf·m}

5. Install the piston into the cylinder barrel

1) Fix the barrel in a vertical or level man-

ner.

2) Install the piston rod into the cylinder

barrel.

★

xed in a vertical manner, the piston

rod falls into the barrel under its gravity.

★

Make sure that the slide ring does not
fall while the piston is inserted into the
barrel.

6. Tightening of cylinder head

Tighten the cylinder head according to the

Rivet

Punch

ZX215-1006183

Tool
Nylon sleeve
(2 pcs type)

(Spread the
gaps by 180°)

ZX215-1006184

Disassembly and Assembly

SY215C

8-93

sequence shown in the illustration on the
right.

Bolt: 267 N·m {27.2 kgf·m}

7. Install the tubing.

Tightening sequence

ZX215-1006185

Disassembly and Assembly

SY215C

8-94

8.23

Work Equipment AS - Remove and Install

8.23.1 Removal

Fully extend the arm and the bucket.

Lower the work equipment to the ground.
Move the hydraulic lockout control to the
LOCK position.

Release residual pressure in the hydrau-

lic circuit. See “Residual Pressure in Hy-
draulic Circuit - Release” on page 6-29.

1. Disconnect the grease hose (1).

2. Lift the boom cylinder assembly (2).

Remove the lock bolt (3).

3. Remove the plate (4) and then the pin

(5).

★

There are shims installed. Count the
shims and check the thickness. Place
the shims in a safe place.

4. Start the engine and retract the piston

rod.

★

Secure the piston rod with a wire rope
in order to prevent the piston from
slipping out. Place the cylinder on a
bench or support. The grease

tting on

the bottom side must be removed in the
later case.

★

Remove the other boom cylinder in the
same way.

5. Remove the two hoses (6) of bucket

cylinder and the two hoses (7) of the arm
cylinder.

★

Cork the hoses to prevent out

ow of oil.

Secure the hoses to the side of valve.

ZX215T-1006186

ZXT225-1106028

Disassembly and Assembly

SY215C

8-95

6. Remove the inter-connector (8) used for

work lamp.

7. Lift the work equipment and remove the

plate (9). Remove the pin (10) from the
bottom.

★

There are shims installed. Count the
shims and mark their locations.

8. Lift and disassemble the work equipment

assembly.

Work equipment assembly:

3578 kg

ZX215T-1006188

ZX215T-1006189

Disassembly and Assembly

SY215C

8-96

8.23.2 Installation

●

Installation is to be performed in the re-
verse order of removal.

★

A clearance (a: 0.5 - 1.5 mm) should be
left between the plate and the nut when
tightening the locknut.

Greasing after assembling the

pin:

Grease (supramoly lithium base)

Do not put your

nger in the pin bore

while aligning the pin bore.

★

Adjust the shim thickness in order to have
a desired clearance (a: 0.5<a<1 mm)
between the piston end (12) and the plate
(4).

★

Standard shim thickness: 1.0 mm and
2.0 mm.

Greasing after assembling the

pin:

Grease (supramoly lithium base)

Do not put your

nger in the pin bore

while aligning the pin bore.

●

Hydraulic oil adding

Add hydraulic oil to the specified level.
Start the engine to circulate the oil in the
hydraulic system, and check the oil level
again. Add more hydraulic oil if necessary.

●

Air bleeding

Bleed the air from travel motor.

For more information, see “Air in Each
Component - Bleed” on page 6-35.

ZX215-1006190

ZX215-1006191

Disassembly and Assembly

SY215C

8-97

8.24 Air Conditioner AS - Remove and Install

8.24.1 Removal

Disconnect the cable from the negative (-)

post of the battery.

1. Drain the coolant.

Coolant: approx. 22.5 L

2. R e c o v e r r e f r i g e r a n t f r o m t h e a i r -

conditioning system with the tool (S).

3. Remove the pad (1) on the cab

oor.

ZX215T-1006192

ZX215T-1006193

Special tools

Part Name

Model

Necessity Qty

Refrigerant

charger

Robinair

34711-2K

●

Refrigerant

charger

Inoue Qing-

Hua

●

Disassembly and Assembly

SY215C

8-98

5. Remove the fuse box (3) and storage

box (4).

6. Remove outer covering (5).

7. Remove the air conditioner cover (6).

4. Open the left rear cover of the cab with

the ignition key. Remove the outer filter
element (2).

8. Remove the back air duct (7).

9. Remove the left air duct (8).

10. Remove the baf

e (9).

11. Remove the right air duct (10).

ZX215T-1006196

ZXT225-1006205

ZXT335-1006999

Disassembly and Assembly

SY215C

8-99

12. Remove the cover (11).

13. Remove the cab's center connector (12).

14. Remove the radio antenna(13).

15. Remove the air duct (14), connector (15)

and air conditioner wiring connection (16).
Remove the two air conditioner relays (17),
three mounting bolts (18). Remove the
electrical mounting plate (19).

ZXT225-1006206

ZXT225-1006207

16. Remove the air conditioner water pipes

(20) and (21) as well as the dripping tube
(22).

ZX215T-1006200

SANY Crawler Hydraulic Excavator SY215CLC (CUMMINS QSB6.7 engine). Shop Manual - page 36