My right Ultegra shifter with 20k miles is failing, shifting both up and down intermittently. I pulled the rear wheel and can see the der and cable do not move correctly sometimes. I have tried spraying and flushing with everything known to mankind (Carb Cleaner, Brake cleaner, WD-40, ATF, Breakfree, Triflow).
The next move is to pull it and soak it in something. I have read that this can sometimes be effective in cleaning it out.
The question is, what is the most effective grease cutting fluid I could use that will not harm the plastic/ rubber parts?
Thanks for any help. I have tried search and just can not get a clear answer.