Following on from an earlier thread about struggling to bleed my rear brake after replacing the old, temperature sensitive m585 calipers with new m59s, I’ve taken folks’advice and tried a bottom up bleed with a syringe after draining the system first (pushing oil through the caliper into the resevoir with a syringe, drawing a small amount back out of the bleed nipple to draw of any air then closing the bleed nipple and working the lever to relase any remaining air through the master cyclinder port).

The brakes now work, which is great but I’m unsure as to where in there travel they should stiffen up (the last time I rode the m585s the temperature was below zero and the pads were in contact with the rotors with the levers released; the levers had virtually no travel – so this is my ‘faulty’ memory of the lever travel). I should have tested them before replacing the calipers, but being a numpty I didn’t.

The pads contact the rotors almost immediately the lever is applied, they stiffen significantly about an inch into their travel but, if I pull hard I can move them to within an inch or the grips. Is the okay or not (the image below shows the levers at absolute max. travel). If this does look acceptable is this how they need to be left overnight to bleed out any remaining air or do I just need to operate them enough to move the pistons? For reference both levers/calipers behave identically.

I think I risk making myself look a ****, but it’s probably best to be safe rather than sorry and you need to learn somehow; do I need to swallow my pride and visit the bike shop? I was hoping to fit hydros. to a bike I’m building up for my partner but unless I get this right I’m not sure I’d be comfortable.

do they stop you? It sounds good to me, but i’d move them in a bit so you can 1 finger brake without squishing the others.

I’d be worried with them that close to the bars – if you can’t get your knuckles behind them when ‘panic braking’ it’ll end in tears.

They look absolutely fine to me (happy user of 4 sets of shimano brakes)
So if they stop you ok, leave them alone!

Cheers, I haven’t ridden them yet, I think that they are probably fine and I’m just confused by the old M585 having difference lever travel depending on temperature (they really were odd in the cold). The lever position shown is the absolute max. I can pull them towards the bars without fear of snapping something, I just wasn’t sure if they should go that close (like I said, the pads hit the rotors almost immediately and both levers have the same amount of travel). Should I leave them that tight overnight for bleed out any remaining air, or just move them in enough to move the pistons and close the system?

Okay, so who tagged my thread with OCD?! 😯

True of course but there’s no need to point it out.

Leave the lever zip tied like that over night and they’ll be better in’t mornin’.

Well a quick dash up and down the road outside seems to suggest that they’re working well enough (although I’ll need to bed the pads in properly to see how they compare with the old M585s). Both front and rear levers stiffen and exactly the same point, which suggests that they’re bled correctly.

They still feel as if they bite later into the lever travel and nearer the bars than the they did with the M585 cailipers but, to the eye the pistons retract a little further and there’s more clearance between the pads than there was with the old calipers; maybe this is a good thing. The only other change is the mineral oil but I guess if fluid doesn’t compress, one brand of oil is going to work the same as another. Any change of componentry has the potential to feel ‘different’ until you get used to it.

I shall give them a good try out when I have the time.