Description

Overview

Automatic Slack Adjuster 28 Spline 6in helps keep brake stroke consistent on truck and trailer S cam brakes by automatically taking up lining wear. This supports safer braking performance when the adjuster is correctly matched, installed, and maintained. It is intended for general purpose applications that use a 28 spline input.

Features

The adjuster design targets simpler brake checks and more reliable adjustment over time. The following features are commonly associated with the Crewson style automatic brake adjuster family:

• Auto Check style stroke checking to support quicker inspection routines
• Cam guard style lubrication pathway to reduce seizing and corrosion risk
• Clearance sensing clutch concept to help control free stroke as components wear
• Sealed gear area intended to limit contamination from water and grit

Specifications and Materials

Part number: FB4998.

See the Hendrickson Crewson brake adjuster overview for general inspection and feature context

However, always confirm the chamber, pushrod, and clevis geometry on the vehicle before installation because small differences can change stroke readings.

Compatibility and Fitment

Match this automatic slack adjuster to a 28 spline, 38mm S camshaft and confirm the 6in arm length suits your existing setup. Verify the clevis pin size and the mounting orientation so the adjuster arm and pushrod travel stay aligned through the full brake application. If you are replacing a failed adjuster, check the cam and bush condition at the same time because a worn cam can reduce service life.

Compliance and Safety

Braking components affect road safety, so a qualified technician should install and set up the adjuster. Perform an initial adjustment, then measure brake stroke on level ground, and recheck after bedding in. Follow the axle or brake manufacturer service instructions for lubrication intervals, torque settings, and inspection limits.

Trailer Applications

Automatic Slack Adjuster 28 Spline 6in commonly appears on:

• semi trailers and B double trailers with S cam foundation brakes
• dog trailers, dollies, and tag trailers with heavy duty brake gear
• rigid trucks and prime movers where the same spline and arm geometry is used

Therefore, treat spline count and arm length as the primary selection criteria rather than relying on visual similarity alone.

Cross-reference and Suitability

At this time, no confirmed interchangeable part numbers were verified from independent sources for this specific listing, so match by spline, arm length, and clevis dimensions instead.

Why Choose ICS Trailers

ICS Trailers helps you select the right braking components by focusing on fitment critical specs and practical selection notes. You can also pair this Automatic Slack Adjuster 28 Spline 6in with related foundation brake hardware and consumables to streamline servicing. Browse Foundation Brakes at ICS Trailers using Browse Foundation Brakes at ICS Trailers