Andrew R Stewart 

I just did a front DA shifter flush and lube at work on Monday. I removed the lever/pod assembly. Placed it in a tub of parts cleaner solvent. Blew it out and cycled through the shifter range a few times then repeated a few times. Sprayed triflow, cycled through the range and blew it out and repeated a few times. Dripped Phil oil into it and cycled/blew a few times. Now it moves real nice with the clicks consistent and sounding new like.

But this didn't fix the real problem of not releasing to allow a full shift off the large ring. When the lever/pod is in one's hand and you work the release lever it's easier if you also counter the release lever's movement by holding the primary (the brake lever blade, the longer one) lever too. In this situation all works well. But when reinstalled to the body (on the handle bars) and only working the release lever the primary lever move inward with the release lever a touch and this blocks out the internals from releasing the spool and achieving a complete down shift.

I have seen this a number of times before and on shifters that were relatively young (therefore not having dried/sticky lube). Shimano's claim is that there has been an internal failure (of a tiny spring I believe) and replacement is the only solution.

If the rider is able/willing to hold the primary lever while also working the release lever then they can have a fully functional shift. I offered this "option" to the customer including it on the work order. I also included an estimate for the equivalent and current replacement (Sora, as it's a 9speed system). I haven't yet talked directly with the customer so don't yet know his choice. Will he be happy with the $25 servicing and modify his shifting technique or go for the $150+ replacements. Andy.