AR42.20-L-0002A | Checking electric pressure governor unit | 22.2.00 |
MODELS 668.###, 670.### ## up to 101650
Vacuum-assisted brake system with electrical air compressor (power brake system)
L42.60-0012-09
A Electrical compressor
B Air drier
C1 Compressed air reservoir V2
C2 Compressed air reservoir V1
D1 Valve pressure limiting valve
D2 Safety valve
D3 Overflow valve
D4 Relay valve
D5 Parking brake valve
E6 Pressure switch I
(spring actuator) B13
F Check valve
G1 Spring actuator
G2 Spring actuator
H1-H3 Test connections
I1 Wire 12x1.5 7.6 m,
12x 1.5 7.9 m (raised)
I2 Intake line
E1 Reservoir pressure switch B12
E2 Pressure switch
(compressor cut-out) B74
E3 Pressure switch II
(spring actuator) B14
E4 Pressure switch
(compressor cut-in) B75
E5 Parking brake pressure switch B5
L42.60-0026-01
E2 Pressure switch
(compressor cut-out) B74
E3 Pressure switch II
(spring actuator) B14
E4 Pressure switch
(compressor cut-in) B75
E6 Pressure switch I
(spring actuator) B13
L42.20-0049-01
| Check | ||
1 | Bleed parking braking system | ||
2 | Connect test kit to test connection (H1) between non-return valve (F) and compressed air reservoir V1 (C2). | Test kit | |
3 | Fill parking braking system with compressed air until pressure governor switches off | Compare cutoff pressure measured at test connection (H1) with specified value. If the measured cutoff pressure and specified pressure are different: | |
Replace pressure switch (compressor cutout) B74 (E2) (blue color coding) | |||
Test kit | |||
4 | Lower reservoir pressure in 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: | |
Replace pressure switch | |||
Test kit | |||
5 | Check control range of pressure governor 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: | |
Check pressure switch (compressor cutout) B74 (E2) (blue color coding) and pressure switch B75 (E4) | |||
Test kit | |||
6 | Remove test kit from test connection (H1) between non-return valve (F) and compressed air reservoir V1 (C2) | Test kit |
Test and adjustment values for parking brake
Number | Designation | Models | |
BE42.20-N-1002-01C | Cut-off pressure | bar | 12.0 (0,5) |
BE42.20-N-1004-01C | Switching range | bar | 10.0...12.5 |
BE42.20-N-1005-01C | Cut-in pressure | bar | 10.5 (0,5) |
360 589 00 21 00
Test kit