Dynafit maintenance is normally pretty minimal and the latest Radical models are considerably more durable than previous models. And the Beast bindings are just bomber. The earlier Comfort & Vertical models have been known to have issues & many of them are now getting pretty long in the tooth so must be examined regularly, which is easy as most of the critical parts on the bindings are visible without disassembly. In my experience any failure is preceded by a visual defect so regular inspection will give you a clue before it happens however if you regularly ski ‘no fall zones’ then I’d recommend upgrading to one of the latest Radical/Radical 2 or Beast models.
On older models regularly look carefully for cracks in the base plate & around the toe pins. I’ve not seen nor heard of a failure on the latest Radical models but I’ve seen quite a few on the older Comfort & Vertical models, especially base plate cracks around the crampon slot & around the mounting holes caused, in my opinion, by the holes being too small in diameter – which is why I always run a 5mm drill though the toe mounting holes on them before mounting them. Inspect for wear of the toe pins/boot toe sockets & deburr if necessary. Whilst not specified by Dynafit, I prefer to keep the toe wings closed to lessen the tension on springs when the bindings aren’t being used for a while. The pivoting toes on the Beast 16/14 and Radical 2 models need lubricating occasionally with Dynafit grease (available from Jon in the 'Dynafit Accessories' section). And a little spray under the toe wings with a silicon lube is a good way to reduce the risk of icing.
If you have removable heel sole plates on your boots make sure they’re screwed on tight. Ensure that the heel inserts in your boots are screwed in tight. Inspect the heel bindings regularly for tightness of the top plate (the only thing holding down the two heel pins). If there\'s any gap between the plates make sure the screws are intact & correctly tightened. If there\'s some vertical movement in the pins, you can disassemble the top & shim up the plastic blocks that hold the pins at the forward end with a layer or two of duct tape before reassembling. Check the heel for lateral stability (Speed Radical heels can also be shimmed up with duct tape under the pivot post to stop this) & check the heel for snappy & accurate self-centering. Sloppy centering could indicate a worn bushing; take the heel housing off & check - it takes lots of turning to actually wear a bushing out, as long as it's lubed correctly. Clean the two springs, the bushing & the post before re-lubing with Dynafit grease (available from Jon in the 'Dynafit Accessories' section). If you\'ve never taken a Dynafit heel apart, read Lou Dawson's instructions at http://www.wildsnow.com before you start.