Is my brake caliper FUBARed – leaking video content

Afternoon all.

I was embarking on my post ‘Puffer brake bleed this afternoon.  Front brake was completely shot.  I could pull the lever to the bar without the (remains of) the pads contacting the rotor.

Bleed kit ordered from Epic Bleed Solutions – check
Kit delivered – check
Instructions read – check
Wheel and pads removed – check
Pistons pushed back in the caliper – check

I noticed a drop of fluid at the base of the caliper at this point.  I pulled the lever and this happened:

Is it terminal?  Its an XTR M9100 caliper, made from a single piece of aluminium so I can’t take it apart to push the pistons out to (presumably) replace the seals which sit behind the pistons..

Arse.

Knackered piston. I’ve had that once before, but the ceramic piston disintegrated on me. It was on the first evening of a biking weekend in Spain. I just stood and looked in disbelief.

At the time, it was bye bye to that caliper, but I understand you can buy replacement pistons on ebay nowadays. No idea how good they are mind.

Terminal unfortunately I think. You can buy seal and piston kits off fleabay but they’re 3rd party and as you say it might be tricky getting the pistons out unless anyone else has had a different experience? I just run deore calipers on all my bikes so it’s the same price for a new caliper Vs the seal kit

XTR warranty is 3 years so if it’s within that and you have proof of purchase then just warranty it.

7 months out of warranty unfortunately.

Reckon you could replace the pistons and seals (it’s just an O-ring on shimano brakes I’ve seen, don’t know if xtr is different) as far as just getting them in, but ideally you need to clean around the seal area. You wouldn’t be able to see what you were doing on that caliper by the looks of it. Awkward job but perhaps worth trying for the £15 cost of a seal kit.

Or just accept shimano planned obsolescence and buy a new one – knowing you’ve got 3 year warranty.

Sounds / looks knackered – I’d buy a new brake – not from Shimano.

You should be able to unscrew the borecap on the outside of the caliper and access the pistons that way, but about the only way you’ll get spare seals and piston is by buying a cheap caliper and transferring the bits over.

(I did this with older XTR 988 calipers some years back.)

Cheers all.

I think I might just take the easier option and replace the XTR caliper with an SLX 4 pot and do the same to the rear when that one bites the dust.

Sounds / looks knackered – I’d buy a new brake

Do you mean “I’d buy a new bike?” far better advice. It’s usually the answer to any bike maintenance question 😂

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Cheers all.

I think I might just take the easier option and replace the XTR caliper with an SLX 4 pot and do the same to the rear when that one bites the dust

So you’re good to reward Shimano for being sh*t by buying another few Shimano callipers that will also likely micro leak at some point in the future?

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If I were that attached to my Shimano levers I think I’d get Magura calipers to go with them – stick the 4 pot Magura caliper on there and get a Shigura which is meant to be the best bits of Shimano and Magura put together.

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What had happened to this forum – it keeps going weird things with quoting now?! The ‘block quote’ function used to work well and now it’s all over the place.

Plus posts take ages to actually go through and it’s stopped recognising the start of a sentence and putting a capital letter at the start. Odd.

Yeah, but there’s a magazine.

It should be standard practise to edit and clean it up before it is presented for reading.

I tried to replace a piston on an older XTR caliper once … couldn’t get the cap off to get the piston out so gave up.

Shigura – didn’t know that was a thing. Looks interesting.

What’s the comparable caliper to SLX?

I’m not overly attached to the XTR, levers but I’m very attached to my bank balance and I want to minimise the cost of this repair.

(New bike is so far off the cards it doesn’t even know there are cards.)

I have replaced the pistons and seals with 3rd part options off ebay. It was a really tricky job but worked very well until they got warmer than usual at BPW, then they started leaking again. I think once they’ve gone they’ve gone.
I’ve just bought a replacement caliper. Which actually, once you factor in 2 sets of contaminated pads, time oil, etc. Isn’t a bad deal…

Mt5 €69 good 4 pot caliper (ignore the e-stop thing that appears to be a combination of pad caliper and disc)

https://www.bike24.com/p2357025.html

Mt5 €69 good 4 pot caliper (ignore the e-stop thing that appears to be a combination of pad caliper and disc)

I’m liking the look of that.

Is that caliper definitely going to work with this:

XTR M9100 > BL-M9100 Lever

Only thing to bear in mind is magura rotors are thicker than shimabo rotors. Sometimes a bit awkward to set up, obviously depends on what rotors you’re running.

might just take the easier option and replace the XTR caliper with an SLX 4 pot

Deore 4-pot caliper and save a few quid.

Let me know if you find any cheap Shimano 4-pot calipers, one of my Zees has just borked.

You can get the piston out by holding the opposite one in place and pumping the brake lever. This pops the opposite piston. But as it is with shimano they don’t do replacement parts for their brakes.

You can get the piston out by holding the opposite one in place and pumping the brake lever. This pops the opposite piston. But as it is with shimano they don’t do replacement parts for their brakes.

Indeed you can Nomadrider, but not when the piston you want to remove is the one that’s leaking fluid. As per the video up there ^^.