Operation
Compression Cycle (Bound): As the shock absorber is compressed by rising wheel the piston rod assembly moves down in relation to the cylinder thus creating a pressure below the piston. The oil flows through the outer ring of holes lifting the flap valve against its spring the volume of the piston rod entering the cylinder displaces an equal volume of oil which is forced through the holes in the valve, past the spring discs and into the reservoir.
Extension Cycle (Rebound): On the rebound the shock absorber is extended reversing the flow of oil. The lower flap valve moves against the helical spring uncovering the inner ring of holes and allowing oil to flow through. As the piston rod is withdrawn from the cylinder an equal volume of oil is recuperated from the reservoir through the central orifice in the valve assembly.
● Servicing of shock absorber
Servicing of this type of shock absorber is confined to renewal of the rubber bushes in the mounting eyes if the existing bushes are worn or perished The internal mechanism of the shock absorber is inaccessible because of the welded construction of the tubes; for the same reason the working fluid cannot normally escape and no means of replenishment is provided. If examination shows that the shock absorber has leaked, it should be removed from the vehicle and a serviceable shock absorber is fitted.
