Adjustment Of Mechanical Brakes - PRONAR T683 Operator's Manual

SECTION 5
During the trailer operation, drum brake linings are subjected to wear. In such a case, the
complete brake shoes should be replaced with new ones. Excessive wear of brake shoes is
the condition in which the thickness of linings which are glued or riveted to steel structures of
brake shoes is smaller than the minimum value. This condition is indicated by extended
cylinder piston stroke. Check technical condition of brake shoe linings through inspection
openings (3) – figure (5.4).
Thickness of brake shoe linings should be checked every 6 months.
TIP
Minimum thickness of brake shoe linings is 5mm.
5.2.7

ADJUSTMENT OF MECHANICAL BRAKES

Considerable wear of brake shoe linings results in increased brake cylinder piston stroke and
worse braking efficiency.
During braking, the brake cylinder piston stroke should be within the specified operating
range and the angle between brake cylinder piston (1) and expander arm (3) should be about
90° – compare figure (5.6). Braking force decreases also when the operating angle of the
brake cylinder piston (5), in relation to the expander arm (1), is wrong – figure (5.5). In order
to obtain the optimum mechanical operating angle, the cylinder piston fork (6) must be
installed on the expander arm (1) in such a manner as to ensure that the operating angle at
full braking is about 90°.
IMPORTANT
Incorrectly adjusted brake may cause rubbing of brake shoes against brake drums, which
may lead to faster wear of brake linings and/or brake overheating.
5.11
Pronar T683