Bendix Automatic Slack Adjusters

How a Bendix Automatic Slack Adjuster Operates

When the brakes are applied, the linear travel of the brake actuator's push rod causes the ASA-5 slack adjuster to rotate the foundation brake camshaft which in turn begins to force the brake shoes into contact with the drum. When the ASA-5 slack adjuster rotates, the yoke assembly pivots on the yoke pin causing the link to be pulled upward.

The teeth on the link mesh with the adjuster mechanism pinion. As the link is pulled it travels first through its free play and then causes the pinion to rotate. Rotation of the pinion is transmitted through the clutch spring to the worm and shaft. Worm and shaft rotation results in worm gear rotation which in turn adjusts (or repositions) the brake camshaft.

When the foundation brake shoes contact the drum, the camshaft begins to resist rotation and friction between the worm gear and worm builds, preventing further rotation of the worm. Brake adjustment ceases at this point and further rotation of the ASA-5 slack adjuster will cause the pinion and clutch spring to slip. The free play between the link teeth and pinion results in a predetermined lining to drum clearance.

Bendix ASA-5 Service Data Sheet with Installation Instructions

Visit the Bendix website to see their full catalog of automatic slack adjusters plus cross reference information.

How do I measure my air brake slack adjuster?
The first step to determining which air brake slack adjuster you need is to measure the diameter of the camshaft at the splines. You will then need to count the splines. Finally, measure the distance from the center of the camshaft hole to the center of the clevis pin hole. This measurement is referred to as the span in the list below.

You'll also need to be aware of any offset from the center line of the slack adjuster arm to the center of the brake chamber push rod. Most of the slack adjusters listed below are not offset. Offsets will be listed in the details for each slack.

A Word of Caution:
Do not mix slack adjuster brands on an axle. For example, don't have a Bendix auto slack on one side and a Gunite on the other. Why? Each brand has a different way of making the brake adjustment, so you will end up with uneven braking.

Click on a slack adjuster below for full details.

	Bendix ASA-5 Automatic Slack Adjuster - 1.25" 10 Spline, 5.5" Span Code: 060-065164 Quantity in Cart: none	Price: $90.03
	Bendix ASA-5 Automatic Slack Adjuster - 1.25" 24 Spline, 5.5" Span Code: 060-065167 Quantity in Cart: none	Price: $87.41
	Bendix ASA-5 Automatic Slack Adjuster - 1.50" 10 Spline, 5.5" Span Code: 060-065170 Quantity in Cart: none	Price: $81.88
	Bendix ASA-5 Automatic Slack Adjuster - 1.50" 10 Spline, 6" Span Code: 060-065172 Quantity in Cart: none	Price: $81.88
	Bendix ASA-5 Automatic Slack Adjuster - 1.625" 37 Spline, 6" Span - Fruehauf Code: 060-065177 Quantity in Cart: none	Price: $92.12