Hi there,

I’ve been running new style Shimano brakes exclusively pretty much since they came out, and while they seem incredibly bitey and responsive while new, or after a bleed and new pads, they seem to consistently have me pulling the lever to the bar a few rides after a new bleed.

I would blame my set, but the same happened with my previous pair, and with a pair on my other bike.
It’s not my bleed; I’ve had them bled by a shop and exactly the same thing happens.
Thought it could be the cheap superstar/uberbike pads I was using, until I splashed out on some Shimano sintered ones and the same thing happened.

It’s as though the pistons don’t move out with the pads as they wear, causing the bite point to get further and further into the lever stroke. The remedy for this is to take the wheels out and squeeze a few times sans rotor, but this is hardly ideal and can lead to rubbing problems.

A good example is my ride today.
I had a fresh bleed from a shop mechanic, & two sets of brand new shimano pads. Brakes felt nice and bitey at the start of the ride.
By the end of a few hours of hard riding in miserable conditions, both brakes were nearly pulling to the bar towards the end of a long descent, which was pretty frustrating to say the least as it was a race run.

I feel like I’ve troubleshooted pretty much everything I can with these bloody things, and I’m wondering if anyone else has similar experiences / can suggest anything that I’m doing wrong / can suggest better brakes to replace them with?

Cheeers

Probably just a one off.

When my old school ones start to fade I just bleed them. I also clean the pots in situ when changing pads and put mineral oil on before pushing back in before putting the new pads in

Tend to be bomb proof

I’m not convinced any brakes are particularly bomb proof as such. Once the newness has gone out of them. Seals wear, pistons get scored, shit gets stuck inside.

This was a bit of a shitter when they cost over a hundred an end but you can get both ends and discs for that now. Shame shimano don’t do spares as it’s a bit wasteful but replacing parts if the system is pretty cheap now. I’ve just paid about the same for a deore caliper with pads as I have for a seal and piston kit in the past.

Anyway, have you tested for leaks at all? lever going soft after a bleed could be a sign of this?

I had a pair of the last gen XTR brakes that constantly had this problem no matter who bled them. One of them was replaced under warranty to the new model XTR Trail (clamp broke) and it still had the same issue. The bite point would always creep towards being at the bar unless you pumped the lever just before you used it.

It definitely wasn’t a problem with the bleed as four different people (including two shops) tried to resolve it but it always came back.

I got absolutely fed up with it and have now replaced them with Formula RO which I haven’t had any issues with. I won’t be using Shimano brakes again in a while!

Probably just a one off.

Do a search – its definitely not
I have one set the do this (XTR) and one set that are the best brakes Iv ever owned (SLX)….although it seems it can happen to any type of new Shimano brake
Weird

You are by far not the only one to have this. I sent mine back under warranty, Madison re-bled them (said oil was black and I had only bled them a week prior!!) and they are ok now. Apparently there are ‘tricks of the trade’ that you now have to do to really make them work consistently. In the end I solved the issue by replacing them with a different brand!

xt (785) and slx (675) over the last couple of years
and not had any troubles at all.

@tom.nash – do you know what the ‘tricks of the trade’ are?

Would be useful to know for those of us who use Shimano brakes and might encounter this problem.

Good to hear I’m not going mad then…
I’ll probably ride my next set of pads out and then think about a new pair of brakes then. Cheers for the input.

Just experienced this yesterday, for the second time!
Once, I would accept but twice now – on separate bikes, both times the rear. (M785) That’s a design or build fault!
I’ll be sending them back under warranty.
Oil is black, clearly some seal degradation somewhere. Suspect the master cylinder seal is wearing where it passes over the ports to its reservoir.