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-   -   Spongy brakes. (http://www.horizonsunlimited.com/hubb/tech/spongy-brakes-43613)

Warthog 18 Jun 2009 21:13

Spongy brakes.
My annual technical review is coming up and I want my little Honda XR to pass!

I have found that my brakes are very spongy. "Lever-to-the-bar" spongy.

Yes the pads are on the way out and should be replaced soonish (<1000 miles) and yes the rubber hose is the original (have ordered bits to make up a braided line) and yes the fluid was old (bled it and renewed the fluid), but the lever still comes back to the bar.

The odd thing is that the bike stops hard long before it reaches that stage, so I would not need to pull it that far on the road, but in the technical checks on bikes they pull it to see and will fail you for it, even if the bike pulls rolling stoppies at half the lever pressure needed!!

So what is the solution? Magura radial master cylinder worth more than the bike?

Seriously, what else could I check to get a firmerlever for the tech check?

Sirakor 18 Jun 2009 22:19

Did you check for leaks? The tiny kind ...

Another explanation would be that you have some air trapped in the line, that wasn't removed by bleeding. I'm told that dismounting the reservoir and keeping it in a place straight and high above the calipers (hose still connected) overnight, can allow bubbles to work their way to the top. Otherwise they might be trapped in a bend of the hose and not get out. Alternatively, reverse bleeding with a giant syringe might get air out, if that's the problem.

Warthog 19 Jun 2009 05:05


Originally Posted by Caminando (Post 246888)
The night before the test, tie the levers back (that is, brakes on)firmly with an elastic of some kind. Next day the brakes will be much improved. I do this often. Try it now and see if it works, before the test day. Let me know your result?

I did that last night also.

The brakes are definitely firmer now. I was in fonrt of the bike so not able to grab the lever as normal, but my guess is it should be fine now for the tech check!

Still does not explain how the brakes can haul the bike up no problem yet the lever can still be pulled back to the bars!! So, enough pressure to stop the bike: where is the rest going? Hose walls?

Warthog 19 Jun 2009 08:27


Originally Posted by Caminando (Post 246930)
It sounds as if you didnt do your rear brake because of not pulling the bike out to access it.

Yes... that's right...not pulling it out...yes.

Laziness? Nooooo! Of course, not: couldn't reach it, yes.....absolutely....:innocent:

Cinquegrana 19 Jun 2009 15:04

I had a similar problem on my KLR. I changed pads, piston seals, fluid even master cylinder.

I swapped out the stainless steal brake line (and bled the brakes) from my Tengai and voila!!! Instant brakes!!!

It looks like the stock rubber brake hose was flexing too much when you applied the brake. Tyr this, pull the brake lever and put your hand around the hose, see if it bulges out a little.... that might be your problem.

Hope this helps, good luck and keep us posted.

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