BRAKE PRO, LTD. TECH BULLETIN

For your information

FOUNDATION COMPONENTS REPLACEMENT RECOMMENDATIONS
Hardware, retainer springs, return springs, pins and bushings should always be replaced with each friction reline!
It is important to remember that all of these items are subjected to very high heat during duty cycles. It does not make sense to try to re-use any of these items, as they are not gong to last. Even if they do seem ok, there is a probability that during the second use you will not achieve your expected life cycle. This in turn causes more intense labor costs and down time, resulting in unsatisfactory cost per mile; they will fail at a shorter duty cycle time thus creating more handling of the vehicle.

S CAMS AND BUSHINGS
S cams should be replaced whenever the wear indicated on the shaft at the bushing area shows marked movement or binding. S cam bushings should always be replaced with each friction reline (see above hardware sentence). Any distortion or wear of the spline area requires immediate replacement of the s cam itself.
When checking for bushing and cam wear, it is important to lubricate the bushing and cam before checking them. It is also extremely important to lubricate the bushing and cam assembly after installation of a new bushing, cam, or both.

SLACK ADJUSTERS (AUTOMATIC OR MANUAL)
Slack adjusters must always be inspected for proper operation and for damage. Any slack adjuster that does not maintain the proper clearance must be replaced, along with the corresponding slack adjuster on the other side of the same axle set. Always replace in pairs, and never mix manufacturers on the same axle.
Before removal, check to see that the slack adjuster is installed correctly and that the home position is correct. When lubricating any slack adjuster, use a hand grease gun instead of a high-pressure grease gun to insure no damage is created to the internal working components of the slack adjuster.

BRAKE DRUMS AND HUBS
Brake drums should never be re-used in heavy service vehicles. Brake drums are one of the most critical areas of difference in severe service vehicles. They are half of the critical balance of heat management in a brake system. Since these vehicles are used in many stops per day, and because the temperatures of the brakes tend to be much higher in these vehicles, there should be no discussion of this requirement.

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