The Bleedin' Brakes!

I've got my front brakes altogether again after a total overhaul. Now I've went through 2 litres of brake fluid trying to sort them out (costs) but the stopping power still is not great.

Defo no air in them, or at least I very much doubt it. Any **** should have cleared with the amount i've bled.

The only idea i've had is to do with when I greased the pistons. I went past half marker by mistake so it's possible grease is in the cylinder (past the seal).

Or any other ideas?

I've got the brake on setting adjustment 1.

Oh aye, and the brakes feel lovely. Very smooth.

That's the grease.


.

I'm not taking them apart again. What about bleeding them with some other liquid (hot water?) to remove the grease and then rebleeding?

[timwilky]

Andrew.

Your brakes are the most important safety device on your bikes. Whilst I would advise every bike owner to have a full understanding of the workings of their bike, they should never compromise their safety on the alter of DIY or cost.

You have already stated that you are not happy with their performance and not prepared to strip them again. At that point hand your bike over to somebody who is more knowledgeable to get it sorted.

Removing the calipers is only a matter of a couple of minutes, They are so simple that there is little to go wrong. Remember that they float on a bracket to equalise the caliper with a single piston, so check they float properly. if your braking ain't great. too much grease can cause a hydraulic lock preventing effective breaking, as much as a seized assembly. So your lines/caliper could be air free and no leaks past your seals.

You did not say if you had replaced the seals. But the best advise is not to get any grease anywhere near your seals. I know some recommend a rubber lubricating grease on the piston seals. but then best stuff has to be a little brake fluid and nothing else.

I could take apart and sort but I can't be arsed

Everything is working like new, just don't quite have the same power as before. I'll try the hot water trick and see if that'll flush them. Nothing to loose.

Don't bleed them with hot water!!
You'll only be adding moisture to the system which will contaminate the brake fluid when you put it back in....
Put a cable tie tight around your brake lever and grip overnight and see if it's improved in the morning. This should force out any remaining air which may be the problem you've got.
I've never used that much fluid on a brake system before, something is not right with your technique.

Hi Andrew,
I understand your torment, I've just overhauled my brakes, and it's a frustrating job.

What type of grease did you get on the seals? I only ask as normal grease causes the seal to swell and stops the piston moving.


www.wemoto.com do a set of new piston and dust seals for £15 inc postage, if it helps.

Good luck.

Cheers burner I'll try that. There was a lot of crap coming out the first lot and constantly feeding new stuff improved the performance. I could keep going but it's getting expensive!

I've no bubbles at all from either calipers so either air is trapped in the calipers? or something else.

It's not bad, locks wheel at low speed but doesn't cut it at 30+.

Greese is Lithium based. All seals in perfect condition so I reused but thanks for the tip. All pistons moving freely. Pads good.