Description

Overview

The TP-5 tractor protection valve is designed to manage trailer air supply and service control in dual-circuit air brake systems, providing protection to the tractor circuits if a trailer fault occurs. It combines several pneumatic control functions in one housing so heavy vehicle combinations remain controllable under line failure. As a result, the TP-5 tractor protection valve helps maintain safe, consistent brake response across both tractor and trailer.

Features

This valve integrates multiple control roles into a compact body, which simplifies plumbing and service work on modern air brake systems. Additionally, it supports stop lamp switch porting to keep the electrical brake signal aligned with air brake operation.

• Combines tractor protection valve and two double check valves in one casting
• Provides service to the trailer from either service circuit of a dual air system
• Includes porting for a brake stop light switch to match air and electrical signalling
• Incorporates a quick release function for the trailer service line to speed exhaust

Specifications and Materials

This TP-5 style valve suits installations where the trailer service and emergency lines must be opened and closed in sequence with the tractor protection function. Service ports front and rear are 3/8″ NPT, while trailer control is 3/8″ NPT and trailer service and emergency supply ports are 1/2″ NPT. The stop light switch port is 1/4″ NPT, allowing a standard air-operated switch to be fitted. The body is typically a robust metal casting suitable for heavy vehicle air brake service.

Part number: AB8442P.

For general background on relay and tractor protection valve behaviour in air brake systems, see this tractor protection valve overview from an independent technical reference source.

Compatibility and Fitment

This cross-reference listing means this valve is a suitable replacement for the part numbers and applications shown. Some changes in air line plumbing may be required. 288605, 104426, 104426X, 289253, 101528, 102638, 103097, 108591, 109663, 288605N, 90HU2B200AA, D7HA2B200, 795036, 445701110A, 42042503, 20QE3234, 2032025C91, 288605B1, SA274, 034082, 193330, 1577393, 79201-3601, 792013601, V1577393, 800024, K023171.

Compliance and Safety

Correct installation of the TP-5 tractor protection valve is critical for compliance with heavy vehicle brake performance requirements. Always isolate and drain air reservoirs before removing or fitting the valve, and use appropriate thread sealant on NPT connections while avoiding contamination inside the ports. In addition, the system should be leak tested, function tested, and road tested in accordance with workshop and manufacturer procedures. Technicians should follow relevant national heavy vehicle standards and the vehicle maker’s service data when adjusting or replacing tractor protection valves.

Trailer Applications

This TP-5 tractor protection valve suits prime movers and heavy tractors operating full trailer or semi-trailer combinations that use dual-circuit air brake systems. It is typically mounted close to the tractor connections so it can protect the service and emergency lines feeding the trailer. Furthermore, it is well suited to fleet applications where consistent trailer brake response and protection against trailer line rupture are priorities.

Cross-reference and Suitability

This part cross-references to or suits the following equivalent part numbers and compatible alternatives:

These cross-reference numbers help workshops match the valve to existing service data and parts catalogues so replacements can be selected confidently for compatible tractor and trailer brake systems.

Why Choose ICS Trailers

ICS Trailers focuses on practical, workshop-ready air brake components that suit hard working trailer and prime mover fleets. Every valve is selected with real world service, availability, and technical backup in mind so workshops can replace parts efficiently. In addition, ICS can support you with related fittings, couplings, and accessories for the complete air brake circuit.

Browse Air Brake Parts at ICS Trailers from our Air Brake Parts category page.