BENDIX TCH-002-005 User Manual

Technical Bulletin

Bulletin No: TCH-002-005 Effective Date: 9/12/2011 Cancels: TCH-002-005 dated 1/2/2007 Page: 1 of 1

Subject: Bendix

Bendix Spicer Foundation Brake LLC continues to use heavy-duty push rods for its Bendix® service brake chambers and spring brake chambers whenever the push rod length provided is eight (8) inches or more. (See dimension A below).

These heavy-duty push rods are manufactured from steel rods with an original diameter of 0.625 inches over the full length prior to threading. Standard push rods are manufactured from steel rods that are only 0.581 inches in diameter. As a result, the heavy-duty push rods are approximately 20% stronger than the standard push rod.

In demanding applications, the heavy-duty push rod resists bending forces (system deection), is more responsive

and out-performs the standard rod versions available in the industry. In addition, Bendix heavy-duty rods are

engineered to meet or exceed the requirements specied for all commercially available slack adjuster suppliers

as of August 2011; Not all standard rod actuators meet these requirements.

Brand Actuators with Heavy-Duty Push Rods

Push rod length ‘A’ is measured from the bottom of the actuator to the end of the push rod. This dimension is taken with the spring brakes released or caged.

Heavy-duty push rod lengths and thread specications are shown below.

3 - 4

inches

max.

Push

Rod

Diameter

Heavy-Duty Push Rods: Threaded Length

Push rod lengths greater than 8, and up to 10 inches - 3.0 inches of threads are provided. Push rod lengths greater than 10, and up to 12 inches - 4.0 inches of threads are provided.

WARNING. Brake actuator push rods that do not meet these recommendations can be permanently deformed by the forces generated during a braking application. Bent brake actuator push rods may negatively affect the braking performance at the wheel end.

Reference

See the following Bendix Service Data sheet available from the document library at www.bendix.com or from the Literature Center at the web site:

SD-02-4525 Bendix® EverSure® Spring Brake