One of my riding buddies turned up tonight with his Shimano XT M785 front brake just pulling to the bars with no spring in the lever or anything. Now my initial thought is bin it and replace like for like. However, sourcing one is not as easy as it should be. Seems everywhere has ceased stocking them apart from one or two places and I can’t find just a lever

So, have Shimano changed this brake too the M8000 series?? And would you buy like for like or go for the M8000

Personally I’d just splash out and get Hope, but it’s not my money

Trying to help a mate out, but need STW’s help

Cheers
Carlos

Sounds like it needs bleeding. How old is it? Does it have any signs of fluid leaks? I would look at fixing it before just replacing it.

Hols2 – can’t see that a bleed will sort it, worked fine at the weekend. Would seem like it’s the usual piston/Spring/whatever bit it is that’s failed and in 99% of cases it’s easier to just replace

Brake is coming up to 2yrs 6mths, no sign of a fluid leak and worked ok on Saturday

Yes, one of my old ones did this. The lever alone, without any hoses attached should ping back but it doesn’t. Little spring or something.

Can’t help on sourcing one sadly but it sounds like that’s what’s needed.

I replaced mine with M8000 eventually. Might be worth seeing if you can run an M8000 lever with an M785 caliper… Hmmm not sure.

Edit. Could be that you can replace just the lever along with the spring, or the spring itself might be available.

This one is from sjs cycles.

I recently replaced the spring on a m785. shimano don’t sell them separately but I asked a guy on here whose seals had gone in the brake itself if I could have a few parts for a pint. replacement was straightforward.

However the spring itself assists in pinging it back and stops the first 2-3mm of play in the lever stroke. it doesn’t provide the only returning force, I think that is largely done by the fluid in the brake itself.

it sounds like the seals have gone.   I fixed mine as they were spare set and it was no rush, if the parts came available then great.

if it was me I would replace the brake to stay riding but keep it and repair if parts become available…. if it isn’t the seals….but it sounds like it is.

Great brakes though

There is an additional Spring inside the master cylinder which sits behind the piston. It’s a real pain to get to.

If the lever is just pulling back to the bars, then the master cylinder piston isn’t compressing fluid. One possibility is the seals in the master cylinder piston aren’t sealing, another is that air has gotten into the system, the last is that fluid has leaked out. It would make sense to find out what’s wrong before spending money.

I just overhauled one of these and the master cylinder was sticking due to slight corrosion.

<span style=”color: #444444; font-size: 12px;”>I just overhauled one of these and the master cylinder was sticking due to slight corrosion.

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I pulled one apart and cleaned the master cylinder, it was still sticky…  worked 9/10 times and then stuck again, then could be freed then worked 9/10 times etc.

I just stuck a £25 M7000 lever on…

<span style=”color: #444444; font-size: 12px; background-color: #eeeeee;”>

Personally I’d just splash out and get Hope, but it’s not my money

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That’s a bit of a jump from £25 to well over £100 and that’s just for a single lever, hose and caliper…vs just sticking on a new lever.  Then bleed kit and one brake on mineral and one on dot ?? or change the other brake as well?

Sounds like a lot of bathwater being chucked out for a single lever replacement.

I’ll have a good look and give it a bleed later, see if that does anything.

If the lever is just pulling back to the bars, then the master cylinder piston isn’t compressing fluid.

My bad, what I meant was its not in contact with anything else and is just a loose free moving lever. Its not even anywhere near the MS piston, that looks like its stuck within the MS itself.

Could be corrosion, may be lack of fluid, might be something else.

That’s a bit of a jump from £25 to well over £100 and that’s just for a single lever, hose and caliper…vs just sticking on a new lever.

True, but if a bike of mine had come with Shimano or Sram brakes I’d have factored in that at some point I’ll swap out to Hope.

I read all these Shimano brake threads and feel glad both my bikes now have Sram Guides! I had an older (old stock but brand new about 6 months ago) pair of deores  on my bitsa hardtail but was very underwhelmed with them.

<span style=”color: #444444; font-size: 12px;”>True, but if a bike of mine had come with Shimano or Sram brakes I’d have factored in that at some point I’ll swap out to Hope.</span>

It’s mostly bling/preference though… Shimano brakes work (mostly) perfectly well…

It’s annoying that they do fail and then need new whole components (lever or caliper) rather than the Hope philosophy of replacing a component small part (the seal etc.) but the levers and callipers are not really that expensive or looking at it another way not significantly cheaper than new pads or rotors which are disposable parts and not much hassle to swap out..

I keep with Shimano brakes mainly as it’s a single bleed kit and set of pads… (across 4 bikes) and replacing those would be something well over £1000 then I would be tempted by some hope rotors etc..

The Shimano levers and calipers are cheap and easy to replace… and not easily serviceable (and mostly not worth it for the cost) ….

I’d probably prefer to buy a bike with Hope already fitted… but I wouldn’t be putting the best part of £300 into changing from decent ZEE, SLX or XT when that’s almost a new shock or drivetrain…

I also stick with Shimano as I don’t want my 8yr old playing with DOT when he’s bleeding brakes or “helping” me do maintenance…

If the master cylinder corrodes, the seals will be damaged if they run across a rough surface. This would explain the lever pulling back to the bars and the piston sticking down. It would also suggest that water got into the system, leading to the corrosion.

Just replace the lever with a M6000 Deore one, they’re £25 new. Job done.

Isn’t the m6000 quite a long 2 finger lever?

I believe the new Deore M6000 brakes are near identical to the M7000/8000 SLX/XT versions, just with less bells and whistles like the tool-free reach adjuster etc.

Like Joebristol I thought the lever was a longer one…. but I might be basing that on the older pre M6000.

I think the callipers changed in the new ones seem to be top loading… which is what I really hated about the older bottom loading ones.  Removing a calliper to change pads always seemed like a breakpoint as does anything not specifically 1 finger…

The older SLX and XT callipers are functionally identical (except they don’t give you a screw)…

I’ve actually taken both apart and then put the left/right from 685 with 785 and they are identical – screw em together and they work…

Bleeding didn’t work, could get any fluid in at the calliper. Spoke to my mate and he said just replace the lot as wants levers to match and I can’t find a right hand lever FS on its own, so complete new brake ordered