Description

Overview

This tractor protection valve three line assembly protects the tractor air system if a trailer line fails. It also provides controlled shut off of trailer supply and service lines. It suits heavy vehicle prime movers and trailer combinations that use three line trailer brake systems. Additionally, the integrated quick release function and exhaust snorkel reduce in cab noise. They vent trailer lines outside the cab.

Features

Key features of this tractor protection valve three line unit include:

• Three line automatic function that manages tractor control, trailer service and trailer emergency circuits.
• Quick release operation that rapidly exhausts trailer lines when you release the controls.
• Exhaust snorkel that directs discharge outside the cab to minimise driver noise exposure.
• NPT threaded ports that simplify plumbing into existing air brake piping layouts.

Specifications and Materials

This valve provides a tractor control port of 3/8in NPT, a trailer service port of 1/2in NPT and a trailer emergency port of 1/2in NPT. It also includes a dash valve or reservoir port of 3/8in NPT and a dash valve signal port of 1/4in NPT. As a result, it matches common heavy vehicle plumbing layouts in local fleets.

Part number: AB8406.

For further technical information on tractor protection valves, refer to this manufacturer technical guide tractor protection valve catalogue

Compatibility and Fitment

This cross-reference listing means this valve works as a suitable replacement for the part numbers and applications shown. You may need to change some air line plumbing. KN34050X, KNX34050, N30073GA, N30073EA, N30073FB, 9348990160, 466890C91, 990690C91, N30073, 767653011455

Compliance and Safety

A correctly functioning tractor protection valve plays a critical role in ADR compliant heavy vehicle air brake systems because it isolates the tractor from sudden trailer air loss. When you install this valve, connect all ports to the correct circuits and use new thread sealant suited to air brake service. Then torque fittings according to workshop procedures. Additionally, always leak test the system and confirm that trailer supply and service lines shut off and reopen according to your fleet standards. During service, check that the exhaust snorkel stays clear and that contamination or moisture build up does not affect valve operation. Otherwise, performance and safety reduce over time.

Trailer Applications

This tractor protection valve three line arrangement typically suits prime movers that tow semi trailers, dog trailers or B double combinations with separate supply, service and emergency lines. It usually mounts in the cab or chassis area near the tractor air tanks, and it interfaces with both foot and hand control valves. Moreover, it works well as a replacement in mixed fleets that already use equivalent three line tractor protection valves.

Cross-reference and Suitability

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

Always confirm thread sizes, port layout and mounting envelope against your existing installation before you finalise replacement, particularly where older or modified trailer brake systems are in service.

Why Choose ICS Trailers

ICS Trailers focuses on practical, workshop ready air brake components for trailers and prime movers so you can match parts quickly and keep vehicles earning on the road. Our team uses real world fleet experience to select tractor protection valves that install cleanly into Australian heavy vehicle combinations, and we back this with responsive support if you need help confirming suitability. In addition, we stock air valves along with associated fittings and accessories to simplify your next service or repair job.

For more compatible parts, browse the Air Brake Parts range at ICS Trailers via Air Brake Parts