[Closed] Shimano Deore Brake Problems

I've got over 20 sets of contaminated pads.

I've put pads in the oven and that's sorted them out a treat (along with the cleaning of rotors and addressing any other root causes, naturally). Never even occurred to me that it might cause a problem with the oven, but then I'm only doing 1 set at a time.

You can get a complete SLX brake set for around £100 if you shop around which, unless you have a particularly cheap source, is a lot cheaper than 20 sets of brake pads. I don't like throwing things away that might be mendable, but I'd have long since given up with your brakes. Life's too short.

[EDIT] are you sure the callipers are leaking? Could it be a bit of careless GT85 getting on the rotors? I also find my brakes get squeaky and less effective, but it seems to be related to not riding enough. Ride more and the problem sorts itself out 😉

are you sure the callipers are leaking?

I've ruled out ALL other possibilities.
Cleaned the Rotors. Even REPLACED the Rotors with brand new. Replaced the pads with Brand new. Bled the brakes until the Levers feel 100%. Kept the bike away from ANY possible contaminate. Tried riding on Road Only with No Mud, No Water and No Cleaning, with New Pads and Clean Discs. The howling still returned a day later.
No Leaks from the hosing after thorough Inspection by myself and the LBT (Local Bike Technician).
It has to be Caliper failure. But why on Earth has it failed so soon ? Why 3X Caliper Failures in a year ? Is it just bad luck or is there something you can do wrong to break them ? Deore can't be that Crap for everyone, they got ace reviews on Chain Reaction and the magazines don't exactly say they're crap.

The Front brake is currently OK but the Rear one still has this problem.

Could it be a bit of careless GT85 getting on the rotors?

I don't use the stuff at all. I don't use any spray based oil at all. The only oil that goes on my bike is chain oil.

Seriously i wouldn't bother spending any more time or money on them. How much have you actually spent buying pads and having them fixed?
As Stilltortoise has said, pick up a set of slx for around £100 and bin the deores.....

You have my sympathy. I had some of the old Deores which were great, and like an idiot, replaced with shiny XTs. Destroyed a lot of pads (though not as many as you) and spoiled quite a few rides before eventually giving up.

Like you, I could put the bike away working just fine, and then take it out again and it would be broken again. The only cure I found was removing the pads when the bike was in the shed, but it's very easy to forget if you come back from a ride knackered. And it shouldn't be necessary.

I've now got Hopes, and you can argue all you like about whether they're as powerful as the XTs, but the calipers don't leak.

pick up a set of slx for around £100 and bin the deores.....

SLX has the same problem. Get something non-Shimano.

Before you cut your losses get some best garden mud and rub it into your disc and go for a good muddy ride.
It might not work but it's free and worth a try.
I have had similar problems on my comuter and this sometimes improve things

Sounds like bad luck. I've had 2 deore calipers fail, but then just immediately replaced them and fine since. Had other shimano's fail too, and it's not worth buggering about changing pads, cleaning etc - just get a new caliper on asap (unless it's the hose).

Other things I've noticed:

Leaks have only occurred on bikes stored for a while. No idea why.
If you need brake cleaner, then the caliper is already gone.
Dusty looking caliper is a tell-tale sign.

I've had 4 sets of the new generation shimanos, deore and XT and not had an issue, guess I'm lucky.

But I'm struggling as to why you've gone through that many pads without just chucking them away and starting again, you must've spent the equivalent of a new set of brakes on pads alone.

I have previously come across a similar issue and changed out the pad to organic pd, as I found that I wasn't getting the sintered pad hot enough to work effectively. Since changing I haven't had an issue.

I've got 2 sets of Deore M615's - both sets do exactly this, fine one ride, crap the next, howling, glazing the pads etc. Seems worse the less frequently the bike gets ridden. It's definitely leaky calipers contaminating the pads, can't be anything else, I've ruled it all out.

I've been through all the same, new pads, scrubbed discs, heated pads, sanded pads, thoroughly clean caliper, check hoses are tight, bleed them, etc, etc. I will say that on a wet and muddy ride they tend to sort themselves out after a few hard stops generally, I've basically given up on trying to sort them out, but if it's dry you ain't got a chance if they're howling from the start.

The set on my Soul are behving at the moment, and will continue to if I ride it at least twice a week I reckon.

I'm going to save up for some Hope Brakes probably.

steve_b77 - Member
I've had 4 sets of the new generation shimanos, deore and XT and not had an issue, guess I'm lucky.

Is there anything that I might be doing wrong that is causing it? Is there any specific sort of cleaning/maintenance that can be done to help preventing it ?

Do you jet wash the bike? I used to, and also had similar(ish) issues (with the same Deore brakes). I was advised / instructed by my LBS to stop jetwashing the s*** out of my bike and since then, touch wood, the brakes work. Might be coincidence though - the instruction from the shop was more about the bearings I was ruining by blasting the grease out. I've also not long had one of the brakes replaced (under warranty) so I might just be tempting fate.

Shimano bulletin:

http://actionwheels.com/articles/shimano-disc-brake-service-bulletin-pg453.htm

Although most cases are due to residual oils, there may be cases of actual leakage (estimated to be less than 2%). In the case of an actual leakage, oil will continuously flow out when the lever is squeezed. If this is the case, please stop riding the bicycle and bring it in for us to evaluate and replace the caliper,

I've just ordered some m615s!

Wasn't the OP the guy paying sub standard mechanics huge piles of cash to do shoddy work?

I've had this on deores and slx. CRC have replaced 2 brakes under warranty but a third that also failed was just over the 2 year mark was returned. Which after a new set of pads and bleed by shimano failed again. At less than 50 an end I'd have chucked then after 3 sets of pads let alone 20!

Hmm, reading all the comments above is making me wonder if my calliper is leaking too 😕

I'd have chucked the lot away a long time ago if it was well-known that Shimano Brakes just don't work most of the time.

But the reviews of Shimano Deore are around 90% positive. I thought I was just having bad luck, so kept spending a bit more at a time, time & time again, hoping it would fix the problem. New caliper £25 x2, new lever £20, new pads £5 each time, mechanic fees for a bleed (I try myself but not always successful) £15 a time, eventually it all added up to so much I'd probably have spent nearly as much as a new set of Hope brakes!

(Although if I get any luck with the Shimano warranty on the original 2x failed calipers and 1x failed lever and also somehow de-contaminate all those pads then I might cover nearly all my losses! Except the mechanic fees for bleeding etc and all those RUINED rides)

My front brake is OK its just the rear that has this problem. Originally both brakes had the problem, when I replaced the calipers, the front was OK but the problem with the rear came back.

Like you, I could put the bike away working just fine, and then take it out again and it would be broken again. The only cure I found was removing the pads when the bike was in the shed, but it's very easy to forget if you come back from a ride knackered. And it shouldn't be necessary.

This actually worked ? I'm going to try this, it might be a lot of faff but at least it's something that can be done to prevent all those ruined rides!
Do the calipers only leak while the bike is stored in the garage ? Do they not leak while on the ride ? Just don't want to ruin yet another set of pads. I hate throwing 'yet another' set of contaminated pads in the "Contaminated Pads Box".

It will at least allow me to "get by" until I fit the new caliper and hopefully get a successful bleed and problem solved. The new caliper I ordered still has not turned up yet.

I never had the pads go from working to not-working on a ride. But I had plenty of times when I had a ride, went home, put the bike in the shed, and then next time, the pads were wrecked.

I wonder whether a seal is drying out? Maybe pump the levers (very carefully so you don't pop out the pistons) just to get things going.

But my investigations can hardly be called scientific. YMMV.

The eventual fix was some Hope brakes.

Wasn't the OP the guy paying sub standard mechanics huge piles of cash to do shoddy work?

Yes, it is he.
Based on all the problems he's had I'm wondering if a different hobby might be for the best.
OP - have you thought about Golf?

On a more serious note, I still think you'd be better off on a hardtail, maybe with cable brakes (BB7s or similar) I think you need to be using simpler tech that can't wrong as easily.

On a more serious note, I still think you'd be better off on a hardtail, maybe with cable brakes (BB7s or similar) I think you need to be using simpler tech that can't wrong as easily

Fair suggestion BUT most of the time hydraulic brakes take sod all maintenance beyond a pad change. Cable discs ime actually need more regular attention especially the one sided ones.

The OP might be better gettingan alternative mechanic to look at it for a second opinion or getting stuck in himself.

OP in your shoes I would possibly bin the hose and the caliper as a minimum and probably buy a complete new brake. I'd then shorten the hose at the lever end (as required/normal) and get it all bled up - get a bleed kit (or use the one you have) and follow instructions/you tube.

MAKE SURE YOU USE A NEW OLIVE if/when you do the hose (i wonder if this has been missed at the caliper end when fixing earlier leaks and it might be worth trying a new olive at the caliper/hose union and checking the hose is snugged up right).

That would take away all reasonable possibility that you have an issue with the hose joint at the caliper and give you a fresh caliper, although think you may already have one ordered.

There are other possibilities here. Not that likely but

1 - do you drag your brakes a lot? I am wondering if you have glazed the pads.

2 - are you using any spray based cleaners or lubes on or around your rear cassette?

3 - do you lay the bike down in the car with the chain dripping with fresh lube (ooo-er)

Edit 2&3 almost certainly will not apply missed that in your earlier post

OP, you don't need to take up golf (at least not because of your brakes) or change your bike, or worry about dragging your brakes.

Your experience mirrors mine. Either be very careful with your pads, or get some different brakes.

One other thing - when I returned mine under warranty to CRC, they gave me the choice of new brakes or a credit note. Like an idiot I took new brakes, which then also failed. If you can, take the credit note.

Today I have replaced the caliper, cleaned the disc and fitted new pads. Obviously the brakes now work, I can use 1 finger on the rear brake again. But for how long? I will have to see how long they last.

If they last more than 2 or 3 rides then I'm doing better than I ever did before replacing the caliper.

If they fail again very quickly then it must almost certainly be a problem with the hosing. Although the hosing has been thoroughly inspected by the LBT (Local Bike Technician)

Dragging brakes ? Maybe sometimes but not all the time, and not any more so than I used to, and I had no problem with Deore's for the first year.

I have had several sets of Deores on different bikes and had no problems with calipers rotors or pads.

Lucky?

That's why I'm wondering if I could be doing something wrong and keep breaking the seals. Is it possible to damage it by pointing the hosepipe at it when cleaning the bike? Might have done that in the past

If they fail again very quickly then it must almost certainly be a problem with the hosing

Nope, could be two iffy calipers. Yes, I think the problem is that common.

That's why I'm wondering if I could be doing something wrong and keep breaking the seals.

e.g. by using the brakes to slow down your bike? C'mon.

My brakes have been perfect since I replaced them with Hopes. I haven't changed the way I brake. Coincidence? You decide.

[quote=nairnster ]I have had several sets of Deores on different bikes and had no problems with calipers rotors or pads.
Lucky?

As I've pointed out on this thread, I've been maintaining a fleet of 40+ bikes with Shimano hydros and had not one problem. IIRC Shimano published some stats saying it was around 2% had some sort of problem?

My brakes have been perfect since I replaced them with Hopes. I haven't changed the way I brake. Coincidence? You decide.

I'd get Hopes if money was no object but for a refunded Deore Caliper (cost me just £5 in postage) or a set of hopes (£300) you can see why I'm trying to give Deore another chance. If it fails again in less than a few weeks then I'm going to be more and more deciding whether to go for a set of Hopes as by then it would leave me with no choice, I can't take this misery forever.

Your experience mirrors mine. Either be very careful with your pads, or get some different brakes.

What do I need to do to be very careful with my pads ? Is this related to installing them more carefully when changing them in future ?? Or be more gentle with the brakes when riding descents ?

Or is some sort of specific cleaning required ?

You've not got owt else in your garage that could be contaminating them somehow have you? Just a thought...

I've got shimano on 3 bikes, 3 levels from Deore up. No problems.

Or is some sort of specific cleaning required ?

Remove them after every ride. That seemed to cure the problem for me, but I only did it a few times, so it might have just been co-incidence.

You might find some used Hopes on the forum here. Also, there are other brands around that don't leak (pretty much all of them).

If I get mine set up right I don't touch them or clean anything until the pads need changing.

You could try bedding a new set in properly. Ride up a steepish hill, drag the brake a tiny bit all the way down to warm it up, then do about a dozen hard stops from a decent pace until you feel it suddenly sharpen up.

Not a lot you can do to be careful with pads other than avoiding spray lubes in their vicinity, or handling them with greasy paws. It's pretty certain that you've had a leaking caliper in the past, and there's always the possibility you'll have another (3 XT's in 2 yrs here), but i've noticed quite a few new systems are coming with traces of jointing compound squeezing out from between the caliper halves, giving credence to the O-ring theory, and also traces around the olive and compression nut too.Hopefully they have it sorted, and yours is one of the ok ones.

Well 2nd ride now after changing the caliper, 63k today, and still no howling! I'm getting my hopes up. Normally if I'd just cleaned everything and changed the pads the howling would be back by now.

You could have genuinely just been unlucky. I've got 3 sets of Deores, vintages 2003, 2009 and 2015 and they have been pretty much faultless.

They don't get much love or cleaning, maybe the dirt is keeping the oil in!

Hope they carry on working for you.

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