OK – will shortly (next weekend) be swapping some Shimano hydro levers on her indoors' bike. They are the older generic Deore style ones.

I am swapping them for the dual control ones in an attempt to solve her gear shifting comfort issues* but that's another matter. I have ordered just the levers (PSA: £30 on CRC) and I have bled these brakes a few times so know my way around generally but wondered whether people had any tips/advice for how to do this…

– Do I need new olives and inserts if just swapping hoses from one lever to another?
– Should I drain the system first and then refill with new levers on?
– If I didn't drain them could I just swap the hose onto the "dry" lever, fill up the reservoir with fluid then bleed to get rid of the inevitable air bubbles between the reservoir and the hose?

They were bled back in June prior to our Alpine trip if that makes any difference…

*have tried a few things already, this is as much an excuse to fettle as anything else

You won't need new olives and stuff, but you might as well bleed the brake system through as you'd still have air in the lever if you tried to fill the reservoir.

Why on earth would you want to give your other arf dual control levers though?! If she has issues with shifting she should either just ride a bit more (it's not THAT confusing!), or just get her Gripshift.

i think he is swapping from the dc levers?

Erm, I am resigned to having to bleed either way, I am asking whether I should just fill it up or whether to drain first. Is it false economy to just do the former option I suppose.

If she has issues with shifting she should either just ride a bit more (it's not THAT confusing!)

She knows how to DO it 🙄 she was having trouble pushing the lever far enough without taking her hand off the grip she said. Tried swapping brake and gears around on the bars but makes it very crowded. Gripshift is the last resort. She may like the dual controls, you never know…

i think he is swapping from the dc levers?

Nope, to them… I am aware that few people seem to like the dual control levers but I'm only really asking about the hose swappage here I guess.

i had em and loved em – they look spazzy thats all

Ho ho, I don't care if they do look spazzy, they're on her bike! 😉

False economy? We are talking about a bottletop amount of mineral oil here. I can't see any point draining the oil out though, and if you've bled them recently anyway, just throw the used oil you catch back in the bottle….

I can't see how Dual Control will help, especially if she has small hands.

I didn't mean financial false economy… Would rather only do it once that's all.

[edit]And I get the impression you can adjust the lever reach on the dual controls…[/edit]