Sunday, August 09, 2009
There is an exploded diagram at bottom of this post.
The Formula Oro Puro disc brake has been around for a few years now. Its a very light brake with good stopping power and modulation.
The only downside I have found is with the FCS (Feeling Control System) adjuster, which can break, in impacts where the lever assembly is pushed "away from the handlebars". When this happens the push-rod usually dislocates from its seat in the end of the "piston" which is housed in the lever or "pump" body (as it is called).
You can usually carry on riding after forcing the push-rod back into the piston-kit Assembly, by applying the brake very firmly, in the normal braking manner, and replace the FCS adjuster later when you have the required tools.
In order to recondition the "pump" body you need to remove the actual brake "lever".There are two types of levers, alloy and carbon.
If you have the alloy lever you need to look carefully inside it. Above the threaded end of the push-rod, recessed into the lever, is a small 2mm grub-screw. This screw fixes the pin which the brake lever pivots on. Loosen the grub-screw a few turns and push out the pivot-pin with the end of a 3mm allen key.
There are actually two types of carbon lever, one has no grub-screw! The pivot-pin lever is "pressed" into place. Carefully tap it out with something of a slightly smaller diameter.
Although you have removed the pivot pin, the brake lever is still attached by the push-rod, to the piston, which is housed in the "pump" body.
Hold onto the brake lever assembly and gently but firmly, and with a lot of force slowly wrench the push-rod out of the end of the piston kit which is still firmly attached to the pump body. It is only held in by a firm "press-fit".
When the lever assembly with push-rod attached, is removed from the pump body, you will be able to see the piston-kit assembly and FCS adjuster are held into the pump body by a small torcx screw. (see above)
If you have broken your FCS adjuster in a crash, or your brake levers are no longer returning to their neutral position after use, you should undo the torcx screw that holds the FCS and piston in place, while keeping pressure on the top of the FCS adjuster in case it flies off after the screw is removed.
If the FCS adjuster is broken, then replace it with a new kit.
If the brake lever was not returning properly then replace the "pump-piston kit" with a new one, after coating liberally with the grease supplied in the kit.
Assemble in reverse order. This time you will need to apply a bit of force when seating the end of the push-rod back into the piston assembly.