CASTOR SAFETY & MAINTENANCE
14
CASTOR SAFETY & MAINTENANCE
In order to ensure the castors are maintained in serviceable and safe
condition, regular inspection is required, especially where arduous
conditions are known to be involved or there is a suspicion of misuse or
abuse. The other key element to ensure is in safe serviceable condition, is
the castor fixing bolt, the condition of which can usually be determined
from the condition of the castor bracket.
The castor is highly rated for the application so if visible distortion is
evident a significant impact will have occurred and under these conditions
the castor and fixing must be replaced.
Typical signs of impact which would require castor and fixing replacement:
It may be thought feasible to repair the castor in a number of these
instances, but serious structural damage will have occurred to the head
bearing and castor assembly as well as possibly damage to the main
fixing bolt. THE CASTOR AND FIXING BOLT MUST BE REPLACED.
When inspecting a castor in order to
determine its serviceability, pay particular
attention to the head swivel bearing
(compare to a new one if possible) and the
boss/rivet which goes through the centre
of the swivel bearing and which clamps the
assembly together.
If the castor is in sound condition,
free from distortion then it may be adequate
to only replace the main fixing
bolt with one of a higher tensile
strength, along with a spacer
washer that enables a higher
bolting torque to be applied.
This will improve the reliability of
the fix, but will not increase the
strength of the castor assembly.
The new fixing nut and bolt are to
be re-torqued to 80Nm.
In order to replace the fixing bolt, the wheel axle
bolt, half nut and star washer will first need to be
removed, along with the central bushing tube
and M12 end washers. This enables the wheel to
be removed so that the castor fixing bolt can be
replaced. When refitting the wheel, the axle bolt,
half nut and star washer, must be replaced with
OEM specification new parts and re-torqued to
40Nm (Pic A). Ensure the axle tube and assembly is lightly greased to
ensure a smooth action when operating the foot brake.
Power Towers Limited strongly recommends replacing any castor
assembly that is over 3 years old with a new one.
Swivel bearing head
should feel free to rotate
and not loose
Castor fixing bolt
Side impact and foot
pedal distortion as a
result of a significant side
impact.
Top mounting plate distortion as a
result of a single significant impact
or multiple lower level impacts.
Even if the rest of the castor is
in good condition, it must be
replaced.
Foot pedal distortion as a result
of a significant frontal impact; it is
likely the top plate and bearing will
be distorted as well.
Pic A.
Important.
These instructions apply to all machines BEFORE
serial no. 26953115C
Castor Fixing Bolt (M12):
Torque - 80 Nm
Castor Axle Bolt:
Torque - 40 Nm
M12 nyloc nut
torque to 80Nm.
M12 standard washer.
Special thin spacer
washer on top of swivel
bearing of castor
M12X60 10.9 bolt