Document 4aaYY0gE8bp5BDje3EpOGp6N1

AMERICAN BRAKEBLOK DIVISION HEAVY DUTY SERVICE BULLETIN BULLETIN NO. 22 ' DOES THE DIRECTION OF CAM ROTATION MAKE A DIFFERENCE? The "S" cam brake usually has the cam turning In. the direction of -- the forward wheel rotation. However, because of hardware accommodations-- it is necessary at-times-to have the cam turn-opposite to-the forward.'-'.-- rotation of the wheel. This opposite or reverse cam rotation can atari'' ' times introduce brake noise, chatter and will result in increased *c,'`' lining wear. "" Reverse cam rotation results in'a 20 to 25% increase in brake torque.^- This increase in effectlveness- is consistent for any given set of braking conditions. . The reason for greater effectiveness with opposite cam rotation is- the jangle of force resulting. In more leverage on the shoe. The re sults of controlled dynamometer^tests and actual field evaluations support this'fact.' - ^-- . - PJM/pnr SCF-ABEX-0024