Description

Overview

The Pacific TP-3 tractor protection valve provides reliable control of trailer emergency and service air supply in heavy vehicle air brake systems. This TP-3 tractor protection valve is designed to protect the tractor brake circuits if trailer lines fail, while still allowing controlled operation of the trailer brakes. As a result, it suits prime movers and road trains where consistent air management and safety are critical.

Features

• Combines trailer emergency and service control in a single tractor protection module for simpler plumbing and service.
• Provides positive protection of tractor air reservoirs if the trailer supply or service lines rupture or disconnect.
• Supports defined operating ranges for tractor and trailer circuits to help maintain stable brake response under load.
• Configured with standard NPT porting so installers can integrate the valve into existing air brake layouts with minimal change.

Specifications and Materials

This TP-3 tractor protection valve suits heavy vehicle air brake systems that use separate trailer emergency and service lines, and it is intended as a direct functional replacement for common OE TP-3 style valves. Porting includes 1/2″ NPT trailer emergency and service outlets, with threaded connections sized to typical Australian prime mover and trailer combinations.

Body construction is a robust cast housing with threaded ports and an internal mechanism designed for frequent cycling in linehaul, local distribution and mixed fleet applications. Internal components are configured for the TP-3 function, with operating ranges matched to standard air brake system pressures.

Part number: AB8439P.

Further technical detail on tractor protection valves in air brake systems is available in this tractor protection valve overview for reference.

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. 279000, 227672, 227672X, 279000R, 243850, 280830, 280932, 288055, 701104, R279000, 825386, 776407C91, 56929AX, 4503M5, 17356002, 801512, S8887, 401228, 034068, 1734941, 25K0645, 524220, 437286.

Compliance and Safety

The TP-3 tractor protection valve operates within typical heavy vehicle air brake pressure ranges, supporting safe isolation of the tractor reservoirs if trailer lines fail. Correct installation helps maintain compliance with heavy vehicle air brake regulations, however final conformity depends on the complete system design and regular maintenance. Technicians should always follow recognised workshop practices, isolate air pressure safely and verify operation with leak and function tests before returning the vehicle to service.

Trailer Applications

This TP-3 tractor protection valve is suited to prime movers, rigid trucks towing full trailers and similar combinations where a dedicated trailer emergency line and service line are present. It fits fleets that use standard TP-3 porting and performance, including general freight, tankers, tippers and curtain siders. Additionally, it is suitable for both new installations and replacement of worn or leaking tractor protection valves during scheduled maintenance.

Cross-reference and Suitability

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

Why Choose ICS Trailers

ICS Trailers focuses on heavy vehicle trailer parts, so buyers get carefully selected air brake components that suit local fleet requirements. The team understands how tractor protection, relay and trailer control valves work together in real world combinations, and they prioritise dependable parts that help keep equipment earning. For support with matching a TP-3 tractor protection valve to your trailer brake system, the ICS team can assist with practical, workshop level advice.

Browse Air Brake Parts at ICS Trailers through our Air Brake Parts category