ar4220d0002a

Checking electric pressure regulator unit

Type ar · topic 42.20 · version 0103 · 2005-09-02

Applies to: MODEL 905.6## #R up to 465741

Where it sits

Function group 2 Chassis › 42 Brakes - hydraulic and mechanical systems › 42.20 Parking brake — Series 905 (models 6**)

EinPAS 21 Brakes/vacuum system/compressed-air system › 21.15 Service brake/vacuum system › 21.15.31 Modulator/brake force regulator — Series 905 (models 6**)

AR42.20-D-0002A

Checking electric pressure regulator unit

26.7.00

MODEL 905.6## #R up to 465741

Checking electric pressure regulator unit

D42.60-1101-09

A Electric air compressor M57

B Compressed air drier with heater

C1 Compressed air reservoir V2 (separate compressed-air reservoir)

C2 Compressed air reservoir V3

C3 Compressed air reservoir V4

D1 Valve pressure limiting valve

D2 Safety valve

D3 Overflow valve

E5 Pressure switch B130
(green color coding)

F Check valve

G1 Spring-loaded cylinder

G2 Spring-loaded cylinder

H1-H3 Test connections

K Intake line

D4 Relay valve

D5 Parking brake valve

E1 Pressure switch B118

E2 Pressure switch B66

E3 Pressure switch B67
(yellow color coding)

E4 Pressure switch B131
(blue color coding)

Checking electric pressure regulator unit
Checking electric pressure regulator unit

D42.20-1102-01

1 Adjustment screw

C2 Compressed air reservoir V3

C3 Compressed air reservoir V4

D3 Overflow valve

H1-H2 Test connections

E2 Pressure switch B66

E3 Pressure switch B67
(yellow color coding)

E4 Pressure switch B131
(blue color coding)

E5 Pressure switch B130
(green color coding)

D42.20-1101-01

Check

1

Bleed parking brake system

2

Connect test kit to test connection (H1) at compressed air reservoir V3 (C2)

*360589002100

3

Fill parking brake system with compressed air until pressure regulator switches off

Compare cutoff pressure measured at test connection (H1) with specified value. If the measured cutoff pressure and specified pressure are different:

*BE42.10-N-1011-10A

Install new pressure switch B131 (E4).

*BA42.20-N-1010-01A

*360589002100

4

Lower the reservoir pressure of the parking brake system until the cut-in pressure of the pressure regulator is reached.

Compare cut-in pressure measured at test connection (H1) with specified value. If the cut-in pressure and specified value are different:

*BE42.10-N-1010-10A

Install new pressure switch B130 (E5).

*BA42.20-N-1010-01A

*360589002100

5

Check control range of pressure regulator between cut-in and cutoff pressure

Compare difference in pressure measured between cut-in and cutoff pressure with specified value. If the difference between the cut-in and cutoff pressure and specified value are different:

*BE42.10-N-1004-10A

Check pressure switch B131 (E4) and pressure switch B130 (E5).

*360589002100

6

Remove test kit from test connection (H1) between check valve (F) and compressed air reservoir V3 (C2)

*360589002100

Parking brake

Number

Designation

Model 905

BA42.20-N-1010-01A

Pressure switch to distributor block

Nm

45

Test and adjustment values for service brake

Number

Designation

Model 905

Model Series 905 up to
R 465741

BE42.10-N-1004-10A

Switching range

bar

10.6...12.5

-

BE42.10-N-1010-10A

Cut-in pressure of electric air compressor, pressure switch B130

bar

-

11.0 (-0.4)

BE42.10-N-1011-10A

Cutoff pressure of electric air compressor pressure switch B131

bar

-

12.5 (-0.4)

Checking electric pressure regulator unit

360 589 00 21 00

Test kit