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303.02.0032 4-circuit protection valve, Brake System

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303.02.0032 4-Circuit Protection Valve for WABCO

303.02.0032

Summary

This 4-circuit protection valve is engineered for pneumatic brake systems in heavy commercial vehicles. It features M22x1.5 and M16x1.5 ports, with opening pressures of 7 BAR and 7.5 BAR to ensure precise pressure distribution and circuit isolation. Equivalent to OE Alexander Dennis 656249, Daewoo 3454402120 and DAF 1505403.

Product identifiers
EAN Code8699031096292
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Compatible OEM Codes

  • WABCO
    • 934 714 125 0
  • OTOKAR
    • 13C2508165AA
  • MERCEDES BENZ
    • 003 431 69 06
  • MAN
    • ZG.04645-0002
  • LOHR
    • F00271322
  • LIEBHERR
    • 502666608
  • FREIGHTLINER
    • TDAS9347141250
  • DAF
    • 1505403
  • DAEWOO
    • 3454402120
  • ALEXANDER DENNIS
    • 656249

Description

What does a 4-circuit protection valve do?

This 4-circuit protection valve plays a critical role in the pneumatic brake system of heavy commercial vehicles by distributing supply pressure to four independent circuits. It is designed to isolate specific circuits in the event of a pressure loss, ensuring that the remaining braking functions remain operational for safety.

Vehicle and system compatibility

The component is compatible with various heavy commercial vehicle brands including Mercedes-Benz, MAN, DAF, and Otokar. It is also widely used in Alexander Dennis, Daewoo, Freightliner, Liebherr, and Lohr vehicles. This part is specifically designed to work with WABCO systems.

Technical specifications and installation

Technicians should note the specific port configurations: Port 1 uses an M22x1.5 thread, while Ports 21 through 24 utilize M16x1.5 threads. The valve operates with specific opening pressures of 7 BAR for most circuits and 7.5 BAR for Port 24, with a consistent closing pressure of 5 BAR across the assembly.

Maintenance and selection guidance

When replacing this component, ensure the new valve matches the existing thread sizes and pressure requirements to maintain system integrity. Consult your authorized distributor for precise fitment verification.

OE cross-reference

303.02.0032 (4-circuit protection valve) is the equivalent of the Alexander Dennis, Daewoo, DAF, Freightliner, Liebherr, Lohr, MAN, Mercedes-Benz, Otokar and WABCO OE numbers. This part directly replaces Alexander Dennis OE number 656249. It also replaces Daewoo OE number 3454402120, DAF OE number 1505403, Freightliner OE number TDAS9347141250, Liebherr OE number 502666608, Lohr OE number F00271322, MAN OE number ZG046450002, Mercedes-Benz OE number 0034316906, Otokar OE number 13C2508165AA and WABCO OE number 9347141250.

Technical Specifications

Technical Specifications
Port 1M22x1,5
Port 21M16x1,5
Port 22M16x1,5
Port 23M16x1,5
Port 24M16x1,5
Opening Pressure 217 BAR
Opening Pressure 227 BAR
Opening Pressure 237 BAR
Opening Pressure 247,5 BAR
Closing Pressure 215 BAR
Closing Pressure 225 BAR
Closing Pressure 235 BAR
Closing Pressure 245 BAR

Other OEMs

ALEXANDER DENNIS

  • 656249

DAEWOO

  • 3454402120

DAF

  • 1505403

FREIGHTLINER

  • TDAS9347141250

LIEBHERR

  • 502666608

LOHR

  • F00271322

MAN

  • ZG046450002
  • ZG.04645-0002

MERCEDES BENZ

  • A0034316906
  • A003 431 69 06
  • 0034316906
  • 003.431.6906
  • 003.431.69.06
  • 003-431-69-06
  • 003 431 6906
  • 003 431 69 06

OTOKAR

  • 13C2508165AA

WABCO

  • 9347141250
  • 934.714.125.0
  • 934 714 125 0

Compatible Vehicles

Compatible Vehicles
BrandModelModel TypeEngine
ALEXANDER DENNIS
DAEWOO
DAF
FREIGHTLINER
LIEBHERR
LOHR
MAN
MERCEDES BENZ
OTOKAR
WABCO

FAQ

What is the main function of this 4-circuit protection valve?
It distributes air supply pressure to four independent braking circuits and isolates them if a leak or pressure loss occurs in one circuit.
Which vehicle brands are compatible with this part?
It is compatible with Mercedes-Benz, MAN, DAF, Otokar, Alexander Dennis, Daewoo, Freightliner, Liebherr, and Lohr heavy commercial vehicles.
What are the thread sizes for the connection ports?
The main Port 1 uses an M22x1.5 thread, while the secondary ports (21-24) use M16x1.5 threads.
What are the typical operating pressures for this valve?
The opening pressures are generally 7 BAR (with Port 24 at 7.5 BAR) and the closing pressure is consistently 5 BAR.
What are the OE reference numbers of this part?
303.02.0032 directly replaces Alexander Dennis OE number 656249. It also replaces Daewoo OE number 3454402120, DAF OE number 1505403, Freightliner OE number TDAS9347141250, Liebherr OE number 502666608, Lohr OE number F00271322, MAN OE number ZG046450002, Mercedes-Benz OE number 0034316906, Otokar OE number 13C2508165AA and WABCO OE number 9347141250.