PREVOST X3-45 COMMUTER User Manual

SECTION 12: BRAKE AND AIR SYSTEM
2
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual Section 12 revised Jan 2021
12.3 FLIP-FLOP CONTROL VALVE (TW-1) ............................................................................................................. 26
12.4 DUAL BRAKE APPLICATION VALVE (E-8P) .................................................................................................... 27
12.4.1 Brake Pedal Adjustment ....................................................................................................................... 27
12.4.2 Maintenance ........................................................................................................................................ 27
12.5 STOPLIGHT SWITCHES ................................................................................................................................. 27
12.6 PARKING BRAKE ALARM SWITCH ................................................................................................................ 27
12.7 BRAKE RELAY VALVE (R-14) ......................................................................................................................... 28
12.8 ANTILOCK TRACTION RELAY VALVE (ATR-6)................................................................................................ 28
12.9 SPRING BRAKE VALVE (SR-7)........................................................................................................................ 28
12.10 PRESSURE PROTECTION VALVE (PR-4) ........................................................................................................ 29
12.11 SHUTTLE-TYPE DOUBLE CHECK VALVE (DC-4) ............................................................................................. 29
12.12 PRESSURE REDUCING VALVE RV-3 .............................................................................................................. 29
12.13 ANTILOCK MODULATOR (M-32QR) ............................................................................................................. 30
12.14 INVERSION VALVE (TR-2, TR-3) .................................................................................................................... 30
12.15 INLINE QUICK RELEASE VALVE (QR-L).......................................................................................................... 30
13. EMERGENCY DOOR OPENING VALVES ........................................................................................................... 31
13.1 EMERGENCY DOOR RELEASE SYSTEM INSPECTION .................................................................................... 31
14. AIR SYSTEM TROUBLESHOOTING ................................................................................................................... 32
15. BRAKE OPERATION ......................................................................................................................................... 32
16. DISC BRAKES .................................................................................................................................................... 33
16.1 INSPECTION POINTS .................................................................................................................................... 33
16.2 VISUAL AND FUNCTIONAL CHECK ............................................................................................................... 37
16.2.1 Wear Check of Pads ............................................................................................................................. 37
16.2.2 Wear Check of Disc .............................................................................................................................. 39
16.2.3 Wear Check of Pad/Disc –Drive Axle – Equipped With L-bracket Wear Indicator ................................ 40
16.2.4 Wear Check of Pads/Disc – Front and Tag Axle – Equipped With Visual Wear Indicator ..................... 40
16.2.5 Continuous Wear Sensor option ........................................................................................................... 41
16.2.6 Checking Correct Functioning of the Adjuster / Checking That Caliper Operates Smoothly Over Its Full
Range of Movement ............................................................................................................................................. 41
16.2.7 Caliper check - Caliper Running Clearance ........................................................................................... 44
16.2.8 Caliper check - Caliper Movement Along Guide Pins ............................................................................ 44
16.2.9 Clearance Measurement Check of Bearing Variants (6) ....................................................................... 45
16.2.10 Checking Sealing Elements – Caliper Guide Pin Seals ....................................................................... 46
16.2.11 Checking Sealing Elements – Tappets and Boot Assemblies ............................................................. 46
16.3 BRAKE PAD REPLACEMENT .......................................................................................................................... 46
17. SAFE SERVICE PROCEDURES ........................................................................................................................... 47
18. AIR BRAKE TROUBLESHOOTING ..................................................................................................................... 47
19. BRAKE CHAMBER ............................................................................................................................................ 50
19.1 MAINTENANCE ............................................................................................................................................ 50
19.2 EMERGENCY/PARKING BRAKE MANUAL RELEASE ...................................................................................... 50
19.3 BRAKE CHAMBER REMOVAL........................................................................................................................ 51
19.4 BRAKE CHAMBER INSTALLATION ................................................................................................................ 51
19.5 BRAKE CHAMBER DISASSEMBLY.................................................................................................................. 51
20. ANTI-LOCK BRAKING SYSTEM (ABS) ............................................................................................................... 52

PREVOST X3-45 COMMUTER Specifications

General

Engine	Volvo D13
Transmission	Allison B500
Fuel Type	Diesel
Length	45 ft (13.7 m)
Width	102 in (2.6 m)
Horsepower	500 hp
GVWR	54, 000 lbs
Height	141 in