Hyundai Excavator R450LC-7. Service and repair manual - page 20

6-41

TEST PROCEDURE

Test 1 : Check resistance at connector

CN-75.

Starting key OFF.
Disconnect connector CN-75 from EPPR
valve at main hydraulic pump.
Check resistance between 2 lines as
figure.

(1)

①
②

③

2

2

)

Test 2 : Check electric current at EPPR

valve.

Install multimeter as figure.
Start engine.
Set the accel dial at "10"(MAX)
Set S-mode and cancel auto decel
mode.
If tachometer show approx 1850

±

50rpm,

check electric current.

(2)

①
②
③
④
⑤

T

T

est 3 : Check pressure at EPPR valve.

Remove plug and connect pressure
gauge as figure.

·

Gauge capacity : 0 to 40~50kgf/cm

2

(0 to 570~710psi)

Start engine.
Set the accel dial at "10"(Max).
Set S-mode and cancel auto decel
mode.
If tachometer show approx 1850

±

50rpm,

check pressure.
If pressure is not correct, adjust it.
After adjust, test the machine.

(

(

3)

①

②
③
④
⑤

⑥
⑦

SPEC : 17.5

±

1

Ω

(20

。

C)

SPEC : 200~450mA(S mode)

SPEC : 5~20kgf/cm

2

(70~280psi)

6-38(2) 210-7

6-38(3) 210-7

6-39(1) 210-7

6-43

TEST PROCEDURE

Test 4 : Check electric current at EPPR

valve at S-mode

Install multimeter as figure.
Start engine.
Set the accel dial at "10"(max)
Set S-mode with 1850

±

50rpm.

Check electric current.

EPPR VALVE

Multimeter

CN-75

Supply line, pilot press

CN-75

Pressure adjusting
screw locknut

(1)

①
②
③
④
⑤

2

2

)

Test 5 : Check pressure at EPPR valve at

S-mode

Connect pressure gauge at EPPR valve.
Start engine.
Set the accel dial at "10"(max)
Set S-mode with 1850

±

50rpm.

Operate bucket lever completely push or
pull.
Hold arm lever at the end of stroke.
Check pressure at relief position.

(2)

①
②
③
④
⑤

⑥
⑦

SPEC : 200~450mA

SPEC : 5~20kgf/cm

2

(70~280psi)

6-44(1) 210-7

6-44(2) 210-7

6-46

TEST PROCEDURE

Test 6 : Check voltage at CN-51(1) and

ground.

Prepare 1 piece of thin sharp pin, steel or
copper.
Starting key ON.
Insert prepared pin to rear side of
connectors : One pin to (1) of CN-51.
Check voltage as figure.

Test 7 : Check voltage at CN-51(13) and

ground.

Prepare 1 piece of thin sharp pin, steel or
copper
Starting key ON.
Insert prepared pin to rear side of
connectors : One pin to (13) of CN-51
Check voltage as figure.

CN-50

Y R G

Multimeter

CN-51

1

12

25

36

24

CPU

CONTROLLER

CN-51

PIN

Ground

Multimeter

CN-51

1

12

25

36

13

24

Ground

(1)

(2)

①

②
③

④

①

②
③

④

2

2

)

SPEC : Actuator stop : 4~5V

Actuator operating : 0~1V

29076MS11