I was on the Raven over a Brechfa today and just at the point when you go down the really steep (for me) bit that you have to hang on and run out (has double !! warning at the top, my rear brake decided to pull all the way back to the bar with no effect. My front started to skid at the wrong moment right at the top so I had to let go and ride it out. Nearly crapped myself.
I’ve just changed the pads so they are new this ride and the bit point is fully in. The brakes are Hope tech X2’s.
Any idea what the cause might be. For a while the back brake has been poor and I hardly end up using any of the pads up before the lever is hitting the bars even with the bite point fully in. The brake feels spongy and short of power as well.
Could it be water or air in the system? Should I try (never done it before) and drain all the fluid out and replace it and bleed?? Any ideas. Ive heard that Hopes are tempremental but it need to get this sorted and am trying to learn new bike mechanic skills rather than give in and take it to the shop.
Cheers.
WJ

Look on youtube for a vid of how to bleed your brakes.
It takes 20mins and is really quite satisfying.
I’ve learnt to do everything so far in this way. If you need a tool then you can justify it in that you’ve saved shop fees and will be able to fix your and your mates bikes again and again.

Sounds like air in the system. Hopes are generally a pretty easy bleed. Find a video, have a go…

Was your bike upside/sideways down for a while? May have been in the car/on a rack/puncture repair. If there was air in the line it may have made it’s way to the calliper end instead of being above the master cylinder chamber by the lever.

Don’t drain and bleed, just bleed to replace the fluid with fresh all the way through. You’ll suck air in if you let it go dry (BAD!).

Well done for riding it out 😯

Dont bleed em.
Just push the pistons right back, take the hose off the caliper and the reservoir cap off and pump the hose and res empty.
Bit of tubing a syringe and some new fluid, fill the syringe and tube full of fluid [do the hospital thing of get all the air out of syringe and tube] Reconnect hose and fill the system through the bleed nipple till the res is full. Dont forget roll your diaphragm.

Aye, don’t drain it.

One common cause is as Herman Shake says- there’s been air in the reservoir all this time, because of a previous bad bleed. Air in the reservoir doens’t cause a problem, til it moves. A correct bleed leaves no air in there to cause you bother but it’s pretty common for people to just do a “good enough” one that works today but might not work tomorrow.

Equally though it’s possible you’ve lost a little fluid so before you do anything else-it’s an open cap design isn’t it? Open it up and have a look, does the reservoir look reasonably full? And are the pads very worn? When the pads are full the reservoir should be full and vice versa.

Cheers for the advice people.

@Herman – it’s been stored the right way up / no punctures etc.
Seems that the consensus is bleed but don’t drain (apart from Dales who I think is saying drain and refill?). I’ll get myself a bleed kit and give it a try, see if it fixes it.
Cheers
WJ

Dales’s method seems hassle to me, why disconnect the caliper hose and risk damage to the hose/olive etc. If you were going for that approach (flushing system from the bleed valve) then I’d leave the hoses connected and collect flushed (old) fluid from the reservoir until new fluid comes through.

Dot listen then, spent lots of time bleeding brakes its pointless. Just filling with brand new fluid is the best way to sort brakes.

Agree (sort of although when I bleed brakes then I effectively replace all the fluid with new stuff). But why disconnect the hose to do this ?

DON’T disconnect the hoses! Just bleed as the hope tech video tells you! Make sure your pads/disc hasn’t been contaminated with oil!

allthepies – Member

Agree (sort of although when I bleed brakes then I effectively replace all the fluid with new stuff). But why disconnect the hose to do this ?

Start with an empty system, then fill from bottom up thats all. It works for Shimano and is effectively what you do with Avids.

Dales_rider – Member

Just filling with brand new fluid is the best way to sort brakes.

If there’s something wrong with the existing fluid. But no reason to think there is. Flushing through gives almost as good a recycle of fluid, and is far easier- recommending someone does their first time bleed from a dry system isn’t that likely to give good results IMO.

ok. I’ll try bleed 1st and see how they ride. Then lesson 2 is to do a complete dry refill. Then I’ll be pro and brake bleeds hopefully 😀
I like learning new skills.

Do shimano/avid recommend removing brake hose when bleeding their brakes ?

I think mr ATP you are missing the point, I haven’t had the need to bleed a brake system for over 3 years.
Because I have closed brake system, much the same as everyone else. If I need to do some work on the system I just empty it and then fill it making sure that I dont put any air into the system, especially when I put the diaphragm back in

Hopes on our bikes do this if turned upside down,

So bike right way up, pads out, push the pistons right back, pads back in, sorted.

So your brakes have been dodgy for a while and you didnt bother to get them checked out?! these are the components that help stop you from flying into trees and huge big rocks at high speeds and potentially messing yourself right up. I take it you realise this now?? When i first started biking about 20 years ago now i was given a good bit of advice and so i feel i have to pass this on to you:

Look after your bike and it will look after you.

You wouldnt drive a car with crappy brakes would you?

I had something similar happen on a long descent in Morocco. I was racing another guy down a long series of double track straights with 180 hairpins every 200m down a steep mountainside. The outside of each hairpin was an almost sheer drop.

On each straight I would stomp out of the hairpin and then brake hard into the next. I was up to a pretty decent lick on one of the straights and just hit the brake before the corner when the rear brake lever suddenly pulled right back to the bar. Holy crap that scared the bejesus out of me – I had no idea my heart rate could jump that quickly! Fortunately, I managed to stop just before the edge on the front brake alone and wait for my pounding heartbeat to subside whilst contemplating the drop below.

Checking the bike over I found that one side of the (almost new) rear brake pads had completely gone…just come unglued from the backing plate and flown off! I’m not going to say which pads they’re not going anywhere on my bikes again!

Agree with the above; don’t remove the hose just do a bleed as per the manual. Flush till you see clean fluid coming out.

If you are paranoid about air in the system; cable tie the lever back after bleeding, leave it overnight, in the morning push a little more fluid through.

i have never taken the hoses off to bleed brakes. EVER. only to cut down hoses or thread the hose through swing arms etc. i use the avid system and it works fine. i flush the whole system but have just had the top cap off my old hopes and put a splash of fluid in before. both work.

@jimification
i think you need to tell us exactly what pads they are bud so it doesnt happen to one of us 😯

@Haggis- that’s been known to happen to Shimano Avid and Hope OEM, Superstar, Disco, Nukeproof, EBC… As far as I can tell it’s just a Brake Pad Thing but when it happens with cheap pads everyone goes ape, when it happens with expensive pads they go “how weird” 😉 Personally had it happen with Shimano and Disco.

PS,

rickmeister – Member

Hopes on our bikes do this if turned upside down,

Get them bled right.

Had the same thing happen to me a few weeks ago and nearly crapped myself 😆

Mine was a slightly lose rear wheel where the rear 9m QR was not done up tight enough. As the wheel was lose and had a few mill sideways play this pushed the pads apart. First time i grabbed the rear brake in anger nothing happened, thankfully a quick pump of the lever sorted it (and then proper tightening of the QR).

You can also get the same effect from badly worn rear bearings, the wheel wobbles and pushes the pads apart and hence feel like brakes need pumping to work.

Steve

Northwind – Member

PS,

rickmeister – Member

Hopes on our bikes do this if turned upside down,

Get them bled right.

Will still happen with any brake if you dont roll your diaphragm !!

Yep, which is part of bleeding right. (or, do whatever the equivalent is for your own brake, not all do it that way) Little point bleeding if you leave air in the res, it’s a snake in the grass.