Hyundai Excavator R450LC-7. Service and repair manual

8-48

Center bypass cut spool assy(24)

Apply loctite to thread of spool, assemble spool end to spool.
Be careful not to appling loctite too much.
Assemble spool assy, spring seat, spring and tighten plug with O-ring.

Tightening torque : 9.5 ~ 11.0 kgf

m(68.6 ~ 79.7lbf

ft)

rm1 regeneration spool assy(20)

Assemble backup rings and O-rings to sleeve respectively.
Assemble piston to sleeve which seal is assemble, and insert spool into sleeve.
Assemble spool assy, spring seat, spring and tighten plug with O-ring.

Tightening torque : 9.5 ~ 11.0 kgf

m(68.6 ~ 79.7lbf

ft)

(

①
※
②

(

①
②
③

8-49

1. REMOVAL AND INSTALL OF MOTOR

REMOVAL

Lower the work equipment to the ground
and stop the engine.

Loosen the breather slowly to release the
pressure inside the hydraulic tank.
Escaping fluid under pressure can
penetrate the skin causing serious in
injury.
When pipes and hoses are disconnected,
the oil inside the piping will flow out, so
catch it in oil pan.

Disconnect pipe assy(4, 5, 6, 7).

Disconnect pilot line hoses(2, 3, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17).

Sling the swing motor assembly(1)and
remove the swing motor mounting
bolts(18).

Motor device weight : 50kg(110lb)

Tightening torque : 58.4kgf

(422.4lbf

ft)

Remove the swing motor assembly.
When removing the swing motor
assembly, check that all the piping have
been disconnected.

NSTALL

Carry out installation in the reverse order
to removal.

Bleed the air from the swing motor.

Remove the air vent plug.
Pour in hydraulic oil until it over flows from
the port.
Tighten plug lightly.
Start the engine, run at low idling, and
check oil come out from plug.
Tighten plug fully.

Confirmed the hydraulic oil level and
check the hydraulic oil leak or not.

GROUP 5 SWING DEVICE(~#0408)

(1)

(2)

※

(3)

(4)

(5)

(6)

※

(1)

(2)

①
②

③
④

⑤

(3)

45078SM01

45078SM02

13031GE18

8-50

2. SWING MOTOR

STRUCTURE

Inner ring

Oil seal

Taper roller bearing

Level gauge assy

Backing spring

Cam plate

Return plate

Piston assy

Lining plate

Plate

O-ring

Piston

O-ring

Spring

Parallel pin

Piston

O-ring

Cap

Scrowave

Teflon ring

Bushing

Balance plate

Needle bearing

Snap ring

Cylinder assy

Housing

Collar

Plug

Snap ring

Bypass valve assy

Back up ring

O-ring

Cover

Time delay valve

Hexagon socket bolt

O-ring

Relief valve

O-ring

Hexagon socket bolt

Check

Spring

Cap

Back up ring

Remove mounting bolts of cover
Loosen hexagon socket bolt(41) with
14mm hexagonal wrench.

Marking at swing motor
Before disassembling motor, make a
matching mark between cover(34) and
housing(26) for easy reassembling.

Removal of make up valve
Loosen cap(44) with 14mm hexagonal
wrench, and remove check valve(42) and
spring(43).

DISASSEMBLY

Removal of relief valve assembly
Remove cap of relief valve assembly(39)
with 14mm hexagonal wrench.
Assemble removed relief valve assembly
(39) to original state when reassembling.

8-51

(2)

(3)

(4)

(1)

※

SM46 (450-3)

SM01 (450-3)

SM02 (450-3)

SM03 (450-3)

Removal of brake piston
When removing piston(12) from housing
(26), there is a sliding resistance against
tightening of O-rings(11,13). Use tap
hole(M6) on piston(12) as shown in the
picture.

Removal of spring(14, break area)
Remove spring(14) from piston(12).
Check and record original position of each
spring(14) for correct assembling.

Remove balance plate
Balance plate(22) is adhered on end
surface of cylinder(25) by oil viscosity.
Take off balance plate(22) with hands.
Assembling method of balance plate(22)
depends on cover(34).
(Band groove and round groove of high

low pressure transmission area)
Before removing, check and record
location of balance plate(22) to prevent
misassembling.

8-53

(

11)

Remove O-rings(11,13) from piston(12)
and housing(26).

(9)

(12)

(10)

SM08 (450-3)

SM09 (450-3)

SM10 (450-3)

SM11 (450-3)

Separate outer race of taper roller
bearing(3) from housing.

Remove friction plate(9) and lining
plate(10) from housing(26).

8-54

(15)

(13)

Removal of cylinder assembly
Holding end of cylinder assembly(25) with
hand, draw out cylinder assembly from
housing.
Oil seal(2) and outer race of taper roller
bearing(3) are left inside of housing.
End surface of cylinder(25) is sliding face .
So, protect the surface with a scrap of
cloth against damage.
Make a matching mark on piston hole of
cylinder(25) and piston assembly(8) to fit
piston into the same hole when
reassembling.

(14)

※

emoval of oil seal

Remove oil seal(2) from housing(26) with
driver and hammer.
Do not reuse oil seal after removal.

(16)

※

SM12 (450-3)

SM13 (450-3)

SM14 (450-3)

SM15 (450-3)

Disassembly of cylinder assembly

Removal of inner race of taper roller
bearing(3).
After removing snap ring(29), lift out
cylinder(25) with 2 inner race of roller
bearing(3) by applying gear puller at the
end of spline in the cylinder.

8-55

(17)

①

Separate cam plate(6), piston assembly
(8), return plate(7) from cylinder(25).

②

Get cam plate(6) slide on sliding face of
piston assembly(8) and remove it.
Be cautious not to damage on sliding
face of cam plate.

③

※

Remove backing spring(5) from
cylinder(25).

④

This completes disassembly.

SM16 (450-3)

SM17 (450-3)

SM18 (450-3)

SM19 (450-3)

When assembling, lubricate with
specified clean hydraulic oil.
When assembling piston assembly(8) to
piston hole of cylinder(25), check
matching mark between them.

ASSEMBLY

Preparation
Before reassembling, perform below pro-
cedure.

Check each part for damage caused by
using or disassembling. If damaged,
eliminate damage by grinding with proper
sandpaper, wash them with cleaning oil
and dry with compressed air.
Replace seal with new one.
Grind sliding face of piston assembly (8),
balance plate(22) and cam plate(6) with
sandpaper #2000.

8-56

(1)

①

②
③

④

⑤

SM20 (450-3)

SM21 (450-3)

SM22 (450-3)

Lubricate specified hydraulic oil on shoe
sliding face of piston assembly(8) and
assemble cam plate(6).

Assemble piston assembly(8) and return
plate(7) to cylinder(25). When assemb-
ling, check matching mark between
them. Before assembling, lubricate
specified hydraulic oil in piston hole of
cylinder(25).

Insert piston assembly(8) in hole of
return plate(7).

8-57

Assembly of cylinder assembly

Lubricate grease on round area
(contacting area with spring(5)) of
cylinder(25) and assemble spring(5).

(2)

①

③

④

②

SM23 (450-3)

SM24 (450-3)

SM25 (450-3)

SM26 (450-3)

Assemble inner race(1) to cylinder(25).

Apply loctite to bearing mounting area of
inner race of cylinder(25) lightly.

Assemble inner race of taper roller
bearing(3) to cylinder(25).

8-58

⑤

⑦

⑥

ssembly of oil seal

Apply three bond of white color on outer
surface of oil seal(2) and assemble and
insert it.
Before assembling, lubricate lip of oil seal
with grease.

(3)

※

SM27 (450-3)

SM28 (450-3)

SM29 (450-3)

SM30 (450-3)

Insert O-rings(11,13) into housing(26) and
piston(12).
Lubricate O-ring with grease.

Assemble plate(9) and lining plate(10).
Lubricate specified hydraulic oil on each
side.

Assembly of cylinder assembly
Hold end of cylinder assembly(25) with
hands and assemble cylinder assembly to
housing(26). Be careful to prevent
damage of seal by spline of shaft.
When assemble cylinder assembly, spline
shaft of cylinder is protruded from end of
housing, therefore put pads with length
30~50mm under bottom of housing.

Assemble outer race of taper roller
bearing(3) to motor housing(26).

8-59

(5)

※

(6)

※

(7)

※

(4)

SM31 (450-3)

SM32 (450-3)

SM33 (450-3)

SM34 (450-3)

Assemble inner race of needle bearing
(23) and snap ring(24) to cover(34).

Assembly of spring(14, brake unit)
Assemble spring(14) to piston(12) of
brake unit.
Insert spring(14) into original position.

Assembly of brake piston
Lubricate specified hydraulic oil on outer
sliding face of piston(12) and assemble
brake piston to housing(26).
It is too tight to assemble piston(11)
because O-rings(11,13) are fitted,
therefore it is recommended to push
piston(12) horizontally by hands at once.

8-60

(9)

※

(10)

Assemble bushing(21) with teflon ring(20)
and coned scrowave(19) to bushing hole
of cover(34).
Lubricate on both end surfaces of
bushing(21) and outer face of teflon
ring(20) with grease and assemble cover
to housing, and parts are adhered on
cover by grease viscosity which makes
assembling easy.

(

※

(11)

SM35 (450-3)

SM36 (450-3)

SM37 (450-3)

SM38 (450-3)

Assemble O-ring(13) to cover(34).
Lubricate O-ring with grease.

Lubricate locating pin for antirotation of
balance plate(22) of cover(34) with
grease sufficiently and install locating pin
to housing.

8-61

(14)

※

Apply three bond of white color to
distinguish oil leakage from remaining oil
in bolt hole(M16) of cover(34).

(15)

(12)

ssembly of balance plate

Assemble balance plate(22) to cover(34).
Be cautious of assembling direction.

(13)

※

SM39 (450-3)

SM40 (450-3)

SM41 (450-3)

SM42 (450-3)

Assembly of make up valve
Assemble check(42) and spring(43) to
cover(34) and tighten cap(44) with 14mm
hexagonal socket bolt.

Tightening torque : 14kgf

(101lbf

ft)

ssembly of cover

Assemble cover(34) and balance plate
(22) to housing(26) lightly, holding them up
with hands.
When assembling, be careful not to
detach balance plate(22) and bushing (21)
from cover(34).
Fit matching marks on housing(26) and
cover(34) made before disassembling.

8-62

(18)

Assembly of relief assembly
Assemble relief valve assembly(39) to
cover(34) with 14mm hexagonal socket
bolt.

Tightening torque : 8kgf

(58lbf

ft)

Be cautious of assembling method.

(

19)

(16)

※

Tighten cover(34) and housing(26) with
16mm hexagonal socket bolt(41).

Tightening torque : 29kgf

(210 lbf

ft)

(17)

SM43 (450-3)

SM44 (450-3)

SM45 (450-3)

SM46 (450-3)

Hyundai Excavator R450LC-7. Service and repair manual - page 28