So I’ve organised a ride for the morning rinsed the bike earlier then put it in the kitchen ready for tomorrow! Then 5 minutes ago I checked my brakes only to fin the rear avid on my ex8 is completely locked up! So much so that I can’t even get the wheel out! Could anyone help pls this has never happened and looks like it’s going to spoil my one day off this week!

Any advise welcome

If you can’t get wheel out. Take caliper off?? Then take pads out give a squirt the push pistons back then squirt gently pull brake. Squirt push pistons back etc. should free it up.

Is it just sintered pads rusted themselves onto the discs? My Hayes nines have all been killed this winter. Spin the wheel with your body weight on the bike ie pedal it to break the bond. Ride it tomorrow and keep your fingers crossed….

I can’t ride it as the wheels locked I’m reluctant to add oil for obvious reasons wtf is goin on??

When did you last ride it?

Have you pinched a hydraulic hose?

I’ve had this with Avid brakes. I think the fluid expands over time. Undo the bleed valve and let a bit out (into a container). Tighten the bleed valve and see how they are.

Don’t put oil on the pads, that will ruin them.

So long as you don’t pull on the brake lever you should be able to move the wheel somehow. Leverage will be the key, sit on the bike and rock it back and forth and the wheel should move.

Once you get it freed up then as above remove the caliper, pull the pads out and try and ease the pistons back in, then pump them out a little and push them back to ease them off.

Take caliper off / remove wheel / gently twist caliper against disk to move the pads apart.

Take the wheel out & prise apart the pads (pistons)

I find a bottle opener is the perfect width & strong enough.

Then work the lever & repeat til freed – worked for me.

Good luck & fingers crossed u get out in the am.

Cheers guys I’ve got the caliper off and pads out I’m just trying to work the piston free. Ahh just what I need on a Saturday night… Ffs

Right so I managed to work them free (removed caliper) pumped them a few times and added a touch of oil!
They went together ok but seem too rub a touch which my front also do. Tbh I’ve had enough I might just bite the bullet and get some shimanos!
Although I can’t believe how useless and problematic these brakes have proven to be 🙁

What “oil” have you added and where? Those seals are designed of DoT fluid and will swell if contaminated with certain mineral oils.

Ha I put a few drops of 3in1 around the pistons to free ten up alittle! They are rubbing abit but I’m not sure what else I could do???

Does it normally live in a really cold shed/garage?

might just be fluid expansion from being in a warm kitchen

bloody avids. had problems myself. never had a prob with big s.

I put oil on pistons and pumped the brakes. also loosened off calipersand tightenedincrementally.

typically if you need to lube the seals you should use the brake fluid the brakes use. oil is not really a good idea.
is now the time to mention i use bb7s?

Yeah it’s in the shed usually, if this expansion theory is right what should I expect/do now?

put it back in the shed 😆

No, seriously, pop it outside for half an hour now or in the morning and if its fluid expansion it should solve itself.

if that doesn’t do it, then you’re going to need to bleed your brakes – though just letting out a tiny bit of fluid might be enough to get you through tomorrow.

Expansion due to temperature change is grasping at some pretty unlikely straws 😀

Engineers do think of these things ya know.

Until the lever (on the bar) is pulled the fluid is not constrained and can expand into the reservoir – more than enough room for the expansion caused by the temperature change from Shed to Kitchen.

Most likely is the pistons in the caliper seizing followed by pads rusting onto the disc.

Most likely is the pistons in the caliper seizing followed by pads rusting onto the disc.

Surely he’d have noticed any rust marks on the disk. OP?

What Avids are they?

I’d take slight issue at “lube the seals you should use the brake fluid the brakes use“…

Seals are designed to resist the attack of DOT brake fluid but it is corrosive and not really a lubricant – it is not intended to be one. It is true to say (IMO) that most car mechanics will happily reach for the brake fluid to lube stuff while reassembling calipers though. It will work but reduce the life of your seal. Silicone is better – one of the fork stanchion products is ideal.

Without thinking this through very hard as it’s bed time, I’m yet again amazed at how much trouble people have with Avid brakes. I love all of mine which are just as reliable as mates’ XT’s. I did have a weird issue one time after refitting a wheel in a hurry though which caused mighty rubbing and jamming. Somehow one of the legs of the spacer spring had been too far out and got mashed in a weird position by the rotor on the wheel being reinserted. Jammed and unridable, replaced pad spring and no problem. Worth a look especially if you take a wheel off for transport…

had no end of probs with avids. got shimano xt now and never had 1 prob. get ur hand in ur pocket mate. save you a lot of f**kin about

Rusted locked brakes are a common problem on cars that have been driven in wet salty conditions then left to stand. Brute force is the answer, the brake will let go with a bang.

Only use silicon spray or dot fluid to lubricate the pistons. When you’ve got them moving pump them out a bit, lubricate, push pistons back in, repeat a few times. Halfords sell big cans of cheap silicon spray. I apply the silicon with a mini paint brush or your Mrs might have a eye liner brush going spare cough cough.

The pistons and seals will swell if you EVER use WD40, GT85 or mineral oil. This will kill your brakes and is a VERY common mistake coincidentally made by lots of the anti-avid brigade.

http://www.merlincycles.com/shimano-deore-m615-disc-brakes-front-rear-set-62194.html

The pistons and seals will swell if you EVER use WD40, GT85 or mineral oil. This will kill your brakes and is a VERY common mistake coincidentally made by lots of the anti-avid brigade.

And these same mistakes magically disappear, when you buy Shimano brakes as the owners become instant experts on brake maintenance.

Shimano brakes receive exactly the same treatment as AVID’s the difference is they just cope with it much better.

Pretty sure it was 3 in 1 that a mate’s wife used to top her Hopes up after shortening the hose, and totalled the diaphragm. I suspect you may be buying those Shimanos pretty soon 😳

Way back when discs first came on mountain bikes, I was asked to sort a set of Hayes on a trek. The system was full of sticky black goo.

Turns out, the customer had been to his local shop first who had bled them like magura brakes, including using magura mineral oil. (the goo was the old seals).

Basically, everything that came apart did, if it was metal, it was cleaned with ipa, if it wasn’t, it went in the bin. That was an expensive bill he passed on to them.

Avid brakes + UK winter trails = problems.

They will work and continue to work but only with careful and regular maintenance. Shimano or Hope are far more reliable in my experience.

Shimano brakes use mineral oil inside them. So putting a mineral based oil gt85 etc on them will do far less harm to the seals than a dot filled system like avid

For me silicon lube every time

I recently bought 2 sets of pistons and seals for my avids, for under £15 from Chain. I measured the pistons and they are a thou or so smaller, so giving a slightly looser piston in the bore. Whether or not Sram knew of the problems and resized them, I don’t know. On a general note, all pistons will seize, whatever the make. If you don’t maintain them, they will seize. Over time you need to service them, in the same way you do wheel bearings, headsets etc. Its a mechanical device.

And these same mistakes magically disappear, when you buy Shimano brakes as the owners become instant experts on brake maintenance.

Shimano brakes receive exactly the same treatment as AVID’s the difference is they just cope with it much better

That’s coz Shimano brakes use mineral oil, Avid brakes don’t. Like I said, common mistake. 😆

Avid’s aren’t designed for vegetable oil either, but that doesn’t stop anyone trying Crisp N Dry.

Got a set of Shimano Deore 515’s that must be over 8/9years old ,other than a couple of bleeds, replacement pads and a upgrade to Goodridge hoses early on in there life they have never been touched.

Certainly never had to mess around with seized pistons or leaking seals I keep threatening to replace them but whilst they keep working there really seems to be no reason.

A friend has the same set on his bike that have NEVER been touched except for new brakepads and again still running faultlessly.

Avid/Sram really need to look at doing some proper testing in the UK as it seems our climate just doesnt agree with there products.

I disagree, every single avid problem I’ve ever seen has been caused by either a squirt of WD40/GT85 or an inability to bleed *correctly*. All components need proper maintenance including brakes.

All components need proper maintenance including brakes.

Handlebar?

Particularly Avid brakes 😉

I have avid brakes and use them in all conditions with no problems. I also have shimano brakes and the same applies to them. The advantage the avids have is that the bleeding is a lot easier as the bleed syringe screws into the caliper and levers, this creates less mess. Avid brakes are also fully serviceable, if you have a problem with a shimano caliper you have to bin it and you can’t get replacement seals. The shimano brakes are very powerful though but a tad heavier.
I think the reason people have problems with avids is because they don’t get to grips with how to bleed them.

All components need proper maintenance including brakes.

Especially brakes. I can live with clunky gear changes, but not stopping….
😉

OP, if you decide to give up my LBS has a great deal on Deores at the moment £67 for a retail pair, with all the spares. (Obviously not adapters and rotors.)

Just as an update thanks to everyone for your helpfull posts. I managed to free the brakes last night by adding a couple of drops of 3in1 then pumped them a few times,all seemed fine so other than a touch of wheel rub (which annoys the life out of me) anyway I went over to lee quarry and had a nice tootle around today.

The brakes worked ok but tbh as soon as I’ve a few spare ££ I’ll be getting some shimanos.

Ben