PRONAR T669XL, Operator'S Manual, Page: 97 / 135

SECTION 5 Pronar T669XL, Pronar T700XL
5.11
While checking pressure pay attention to technical condition of wheels and tyres. Look
carefully at tyre sides and check the condition of tread. In case of mechanical damage
consult the nearest tyre service and check whether the tyre defect requires tyre replacement.
DANGER
Damaged tyres or wheels may be the cause of a serious accident.
Wheels should be inspected with regard to distortion, breaking of material, breaking of welds,
corrosion, especially in the area of welds and contact with tyre.
Proper technical condition and appropriate maintenance of wheels significantly extends the
life of these components and ensures appropriate level of safety to trailer users.
Checking air pressure in tyres and visual inspection of steel wheels:
•
every month of use,
•
every week during intensive work.
5.2.8 MECHANICAL BRAKES ADJUSTMENT
Considerable wear of brake shoe linings results in increased brake cylinder piston stroke and
worse braking efficiency.
TIP
Correct brake cylinder piston stroke should be within the range of 25 – 45 mm.
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 (5.8), (5.9). Trailer wheels must brake simultaneously.
Braking force decreases also when the operating angle of the brake cylinder rod (5) – figure
(5.6), (5.7) in relation to the expander arm (1) is wrong. 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°.