Why won't my brakes work!?!?! - (free beer content)

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Why won't my brakes work!?!?! - (free beer content)

21 posts & 12 voices | Started 2 years ago by Practical Matt | Latest reply from ahwiles

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Practical Matt - Member

OK I bought some 2010 (I think) SLX levers brand new last month to replace the horrible 2007 flappy paddle xt all in one shifter levers units my bike came with.

I was recomended that if I was carefull I could disconnect the hoses from the old units, connect them to the new ones olive and all and then simply blead out any air and I'll be ready to go. Sounds simple doesn't it?

I followed the instructions in my manual and the stuff that came with the levers, but I just can't get it to work. There is no build up of pressure in the levers, they just flap about and I can't see any evidence of the pads moving when I depress the levers having sealed them all up.

Are the hoses/olive/valves diferent sizes?

Any help or answers greatfully recived or if you live in Notts I will gladly supply a crate of beer of something in return for a visit and some working brakes. I've booked Friday off work to go riding and really don't want to let my mates down.

Posted 2 years ago #
scaredypants - Member

is there anything in the reservoirs ?

Posted 2 years ago #
Spankmonkey - Member

did you fill the lever end up with oil ? if not fill it up, upen up the piston end bleed nipple then pump the brake, repeat around 10 times to get the air out each time topping up the oil, then seal both ends and pump the brake again!, if they are different sizes you would have oil escaping.....

Posted 2 years ago #
bereavementmonkey - Member

Shimano or normally pretty interchangeable and certainly one of the easiest sets of brakes I have ever bled!

Did you bleed them with the wheels IN? wheels out pads in then try it again dont forget to tap the hoses, calipers and lever cylinders to make sure all the air is coming out.

Not sure how much help this will be.

Posted 2 years ago #
tinsy - Member

You might consider a change of user name...

Posted 2 years ago #
Practical Matt - Member

I connected a bleed bottle to the bleed valve, opened the valve and filled the reservoir. cranked the levers and topped up the reservoir as it emptied.
The bleed tube started to fill with pink fluid from the fluid bottle.
I tightened up teh bleed valve and filled the resrevoir to the top, sealed it and teh levers still got all teh way back to the bar without any resistance.
Am I supposed to shut off the bleed valve in between pumps? I thought I was supposed to fill the system till it was in effect bleeding right through and then seal it all up.

Posted 2 years ago #
Practical Matt - Member

Tinsy, yes you have a point

this is the first time I have ever been stumped by anything mechanical or practical. I feel so ashamed (and stupid)

Posted 2 years ago #
stratobiker - Member

Practical Matt,
Great username!
Assuming it all seemed to connect up OK, no problems, and you don't have oil pissing out.

Move the bike, and adjust the angle of the lever so that the you have the caliper lowest, then an uphill run to the lever, which you will set at level (Like, for the back brake, stick the front wheel on a chair). Remove the cover from the reservoir on the lever. You've set this level, so it shouldn't run out. First, the reservoir should be full, so if it ain't top it up with the right oil. Next, use a small screwdrider, or spanner or something and gently tap the brake hose. The idea being to get any small bubbles in the brake line to move upwards towards the surface. As you do this gently pull and flick release the brake lever. Watch for any tiny bubbles.

When you've done that for a while, top up the reservoir and refit the cap. It would be normal for the rubber insert that goes under the cap to force some oil to spill when you refit it. This makes sure that the system is full.

Don't overtighten the reservoir screws.

HTH
SB

Posted 2 years ago #
bereavementmonkey - Member

http://www.veoh.com/collection/ExtremeBiking/watch/v18310552K8TeM4Qd

should help

Posted 2 years ago #
BigJohn - Member

With my hopes I

1 undo bleed nipple
2 squeeze lever
3 tighten bleed nipple
4 release lever
5 check/top up reservoir

repeat till all bubbles gone and new fluid is being expelled.

Posted 2 years ago #
stratobiker - Member

Ah, I now see that you've opened the bleed valve.

So you've gone for a full bleed.
Forget what I said above. It's too late!

Yes, You must close the valve when you let go the lever.

Posted 2 years ago #
sobriety - Member

Where in notts are you? If you're local to me I could have a look, having bled a couple of sets of XTs with no bother, although I can't promise to be anymore practical than you!

Posted 2 years ago #
Practical Matt - Member

Sobriety- I'm in Gedling, just off Westdale lane.

Posted 2 years ago #
retro83 - Member

You need to do what big john suggests. You do need to close the bleed nipple after pulling the lever back to get fluid going into the system

Posted 2 years ago #
Practical Matt - Member

OK I'll get the valve closed and get cranking tonight, possibly after buying another bottle of fluid.

Although anyone who wishes to help or just point and laugh is still welcome to come to my aid.

Posted 2 years ago #
sobriety - Member

I'm in Sneinton, well i will be when i get home from work, i'll dig out my bleed syringe and head over this evening/tomorrow evening (whatever's easiest for you) if you drop me an email of your address and what time is best. Email is in profile.

Posted 2 years ago #
thisisnotaspoon - Member

Preperation:
resevoir cap off, and diaphragm if there is one
lever level with the ground
caliper orientated to get the bleed nipple as high as possible

ring spanner and clear pipe on the nipple

resevoir 3/4 full

ALWAYS WEAR GLOVES AND EYE PROTECTION!!!!!!!!!!!!!!!!! 3.99 for some halfords goggles Vs brake fluid in the eye doesn't bear thinking about

Now do the folowing

Squeeze lever to put presure in the system

open nipple 1/4 to 1/2 a turn

allow fluid to escape into pipe

close nipple before the lever reaches the bar/limit stop, impractical untill its at least partialy bled i know, but more important once most of the air is gone. Never release the lever with the nipple open.

Close nipple

Release lever slowly (or you'll get a face full of brake fluid as it squirts back into the resevoir)

Check resevoir level, top up if nececary

Repeat the process untill fresh fluid is coming through with no air in it.

You are using shimano mineral oil arent you, not dot3/4/5.1 fluid which will ruin the seals?

Posted 2 years ago #
Practical Matt - Member

oh yes shimano oil that came with the levers.
and eye protection- I am Practical Matt after all
although I may have to temper this name to Relativly Practical Matt after this episode.

I wish more manuals were written by comitee like this.

Posted 2 years ago #
ziggy - Member

Sounds like you are doing it all wrong to me.

First off remove pads and make sure pistons are fully retracted.

If you are bleeding Shimano brakes correctly there is no need to even touch or squeeze the lever.

All you need to do is attach the bottle to the bleed nipple on the caliper and push the fluid UP. Keep doing this until 30 ml has gone through the system, replace reservoir cover and you should be finished.

Posted 2 years ago #
Practical Matt - Member

Sobriety- mail is in your in box.

Hopefully see you tonight.

Posted 2 years ago #
ahwiles - Member

i've never had a problem bleeding shimano brakes...

using a small syringe, and a length of windscreen washer tube, push oil in from the nipple, easy.

once the system is full, squeeze the lever a few times to encourage the last few bubbles out.

but yes, you can swap hoses over from lever to lever without new olives.

Posted 2 years ago #

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