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303.02.0085 4-circuit protection valve, Brake System
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303.02.0085 Compatible 4-Circuit Protection Valve

303.02.0085

Summary

This 4-circuit protection valve is designed for heavy commercial vehicle pneumatic systems. It features M22x1.5 and M16x1.5 port sizes and specific opening pressures (6.8 BAR for circuits 21, 22, 24 and 7 BAR for circuit 23). Compatible with Volvo F-series, FL-series, NL-series, and B-series trucks. Equivalent to OE Knorr-Bremse AE4428 and Volvo 8152899.

Product identifiers
EAN Code8683457009448
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Compatible OEM Codes

  • KNORR-BREMSE
    • AE 4428

Description

What does a protection valve do?

This protection valve plays a critical role in the pneumatic brake system of heavy commercial vehicles by distributing supply pressure to four independent circuits. It ensures that any pressure loss in one circuit is isolated, maintaining the integrity of the remaining braking functions. Built with high-strength components, it provides reliable performance under demanding operating conditions.

Compatible Volvo models and engines

The component is engineered for compatibility with various Volvo models including the F10, F12, FL10, FL12, NL10, NL12, B10B, B10M, and B12. It is also suitable for vehicles equipped with TD102, TD122, TD103, D10A, TD123, or D12A engines. This valve is designed to function within Knorr-Bremse systems and is an equivalent for Volvo OE specifications.

Technical specifications and installation

Technicians should note the specific port configurations: Port 1 uses M22x1.5 while Ports 21 through 24 utilize M16x1.5 connections. When performing maintenance or replacement, ensure that the opening pressures (6.8 BAR and 7 BAR) match the vehicle's pneumatic requirements to maintain correct braking sequence and pressure balance.

Selection guidance

Consult your authorized distributor to confirm exact fitment for your specific chassis configuration.

OE cross-reference

303.02.0085 (4-circuit protection valve) is the equivalent of the Knorr-Bremse and Volvo OE numbers. This part directly replaces Knorr-Bremse OE number AE4428. It also replaces Volvo OE number 8152899.

Technical Specifications

Technical Specifications
Port 1M22x1,5
Port 21M16x1,5
Port 22M16x1,5
Port 23M16x1,5
Port 24M16x1,5
Opening Pressure 216,8 BAR
Opening Pressure 226,8 BAR
Opening Pressure 237 BAR
Opening Pressure 246,8 BAR
Closing Pressure 213,8 BAR
Closing Pressure 223,8 BAR
Closing Pressure 235,5 BAR
Closing Pressure 243,8 BAR

Other OEMs

KNORR-BREMSE

  • AE4428
  • AE 4428

VOLVO

  • 8152899

Related Products

Repair Kits

Compatible Vehicles

Compatible Vehicles
BrandModelModel TypeEngine
KNORR-BREMSE
VOLVO
VOLVO B10B D10A
VOLVO B10M D10A
VOLVO B12 D12A
VOLVO F10 TD102
VOLVO F12 TD122
VOLVO FL10 D10A
VOLVO FL10 TD102
VOLVO FL10 TD103
VOLVO FL12 TD122
VOLVO FL12 TD123
VOLVO NL10 D10A
VOLVO NL12 D12A

FAQ

What is the function of a 4-circuit protection valve?
It distributes air pressure to four separate circuits and isolates them if a leak occurs, preventing total brake system failure.
Which Volvo models is this valve compatible with?
It fits various models including Volvo F-series (F10, F12), FL-series (FL10, FL12), NL-series (NL10, NL12), and B-series (B10B, B10M, B12).
What are the port sizes for this component?
The main port (Port 1) is M22x1.5, while the distribution ports (Ports 21-24) are M16x1.5.
How can I ensure correct pressure settings?
Check that the opening pressures align with vehicle requirements; typically these are 6.8 BAR or 7 BAR depending on the specific circuit.
What are the OE reference numbers of this part?
303.02.0085 directly replaces Knorr-Bremse OE number AE4428. It also replaces Volvo OE number 8152899.