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Thursday 29 January 2015

New balls please!

During the door repairs I noticed the front suspension going a bit stiff. A straight forward replacement of the front suspension spheres sorted this out. The 59bar nitrogen gas in the top half of the sphere had lost pressure through a deteriorated diaphragm. Always good practice to replace the hydraulic seals when a component is refitted, at the most you would have to replace four here as there is a little extension piece which fits between the sphere and the suspension cylinder and invariably comes off with the sphere. Cleanliness is paramount during this operation, clean all the loose build up of crap from around the top of the cylinder before removal, the last thing you need in your hydraulics is some grit floating around. (I used compressed air, but watch your eyes and use goggles)

From Wikipedia:

Pressure flows from the hydraulic circuit to the suspension cylinders, pressurizing the bottom part of the spheres and suspension cylinders. Suspension works by means of a piston forcing LHM into the sphere, compacting the nitrogen in the upper part of the sphere; damping is provided by a two-way 'leaf valve' in the opening of the sphere. LHM has to squeeze back and forth through this valve which causes resistance and controls the suspension movements. It is the simplest damper and one of the most efficient.

N/S/F suspension sphere

O/S/F suspension sphere, the extension piece can be seen here