Shimano SLX caliper leaking at pistons, repairable?

Just bled my front brake and got the lever nice and firm. I had reset the pistons and used a bleed block during the bleed. I then refitted the part worn pads and wheel and whilst working the lever to extend the pistons onto the old pads I noticed a leak from the caliper. Re bled and firm again with no leaks with the bleed block in position, but leaking (a lot) from around the piston when I work the lever against the part worn pads. Is this a knackered piston seal, is it repairable or a new caliper? I will probably take it the lbs tomorrow but I had a load of riding planned this weekend, doh!

New caliper or new brakes – typical Shimano issue unfortunately.

Yes it’s bolloxed, but a common item so probably held in stock in a LBS. Good interchangeability between most shimano calipers AFAIK so you wouldn’t even need to match it with an slx if there was a problem finding one.

If it’s slx you need a slx or xt caliper due to the banjo mount on the hose (lower ones are inline).

Thanks chaps, LBS it is tomorrow morning. I’m lucky enough to have Pearce Cycles a mile and a half away. I hope they can turn it round quickly though as I had a fair bit of riding planned over the coming week, not least to maintain my mediocre fitness for Heaven of the South in a fortnight.

Shimano OEM spares (seals or pistons) are not available. When I looked at the cost/hassle of rebuild with industrial seals or aftermarket piston I decided to just get new calipers given that I needed new pads anyway. I felt guilty because Shimano’s “chuck when you get a leak” is an environmental disaster and I should have bought e.g. Hope’s that are properly supported.

In warranty?

Are Pearce up & running again after being robbed last week?

In warranty?

Dunno tbh? It’s newish used, a 2018 ex demo Giant Trance 2 bought from a Giant dealer (not local to me) 4 months ago. Not sure of the warranty situation. I may call them tomorrow but the hassle of getting the bike to them and potentially being without it for longer may mean it’s less hassle to bite the bullet and pay my LBS to fix it.

Are Pearce up & running again after being robbed last week?

Yes, called in on Tuesday and bought some riding glasses. Open but a bit chaotic (understandably). Gutted for them.

2 year warranty on those I think.

There are replacement piston/seal kits available on ebay. I’d like to try one but I’ve yet to have a Shimano caliper fail.

@scotroutes those are the ones I looked at but note they’re around £7 for 1, i.e. a caliper’s worth is £14. A whole new caliper can usually be had for £25 and includes a new pad and warranty .

I’ve a brand new caliper that failed around the pistons on initial bleed. Half tempted to try those pistons.

@scotroutes those are the ones I looked at but note they’re around £7 for 1, i.e. a caliper’s worth is £14. A whole new caliper can usually be had for £25 and includes a new pad and warranty .

Aye, but folk are also saying they don’t like buying new due to the “disposability” aspect.

The bike is in with Pearce and a new caliper has been ordered. Said they’d just fixed one with an identical issue and that it happens a lot with Shimano brakes. Because of the bank holiday it will be Wednesday at the earliest before I get it back. Such is life. Haven’t bothered with checking out the shimano 2 year warranty as I can’t get hold of anyone at the shop I bought it from which is not local, and I imagine the claim procedure would delay me getting back on the road even more. Pearce are charging me £35 for the caliper, plus fitting which I don’t think is bad for a small LBS. Frustrating that I will be slightly out of pocket for a defective component, but I just want to get out and ride so pragmatism overrides patience and thrift!

Tbph, I really don’t understand this.

Shimano don’t want their brakes to be repairable but don’t want to fix the long-standing leaky seal issues.

People dislike having to replace as unit and dispose of item that would be easily repaired if parts available. Aftermarket parts are now available but at a cost which discourages use – and based on threads with people trying to diy the things may well be a short-mid term consumable as opposed to actual ‘fix’.

Why do people keep buying Shimano brakes? At the Deore end I can see the point as they’re still better than most other budget options. But by the time you’re looking at XT money, there are options that variously out perform by a country mile and/or have easy parts availability and service friendliness designed in. I can only think it’s to do with the power of advertising and magazine reviews…

Why do people keep buying Shimano brakes?

In my case, every pair I have (and have ever) owned have worked perfectly. From working in bike shops and in maintaining a fleet of 60+ hire bikes for a few years, my own experience is that the number of failures is miniscule when compared to the number of units shipped.

Search through the ‘net and you will find horror stories of SRAM/Avid, Hayes, Magura and others, many of whom ship only a relatively tiny number.

The Hope alternative is expensive and not without its own serviceability issues (there’s a very good reason bike shops hold Hope spares).

Also, the calipers are aluminium which will be recycled if you chuck in a recycling bin so it’s not like they’re just going to landfill.

Don’t think your supposed to stick amy old alloy/metal in the recycling bin but yes it can at minimum go to the household waste sites.

Why do people keep buying Shimano brakes?

I had XT caliper fail and lever fail twice so looked elsewhere. Hope were literally twice the cost of XT, and personally I still prefer the performance of XT. I went with the Hopes, but it’s not hard to see why people don’t.

I want rid of mine. The performance is fine but I’ve has 3 or 4 caliper failures now.

Justed looked again the the eBay pistons. Some are metal only which would be crap for performance when hot. There is a reason most pistons and phenolic plastic.

Nobody ever tried measuring up the seals for replacements?

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F253219864542

Two seals for less than a fiver – I’d try that as an experiment on the rear caliper, at least, before binning. Keep reading about leak problems but haven’t had any myself.