Spongy front brake

Taotao Paladon 150 (CY150). If I pull the front brake the lever almost touches the grip. I have bled the hell out of this system and there was/is no air in it as far as I can tell. It's not spongy like air, it's spongy like cheap brake hose that is expanding.

I notice that about 50% of the lever travel is just to move the pads to the rotor (about 1 or 2mm), then it's spongy.

Assuming the spongyness is just the hose expanding, anyone have any tricks to eliminate that first 50% of travel before the brakes contact the rotor? I think if that wasn't there the brake would at least be usable. Right now it smashes my fingers on the grip before I get full braking.

I think the piston in the caliper may be sticking or something. In other words the self adjustment is not working. I'm going to try removing it and opening/closing the caliper to see if it loosens up and starts adjusting correctly.

Are there better forums than these where technical people hang out?

Edit:
I worked the piston in and out and it doesn't seem to be sticking. When I put it back together I closed the caliper one more "click" than normal so it was tighter on the rotor. This seems to have helped with the initial travel. I think the master cylinder is just releasing the piston too far on the back stroke. Poor master cylinder design or could it have a problem?

I also played around with the "ABS" pre-load and that seems to have an effect on the spongyness. I need to remove that piece of crap. I believe I need a new banjo bolt to do that though. Anyone know?

Perhaps it would help if you fitted a steel braided brake hose, it might not completely fix the problem but it should help.

Failing that you could try rebuilding the brake calliper, you will be able to see if there is any damage to the seals or rust inside.

Quote:

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Originally Posted by sprok

Taotao Paladon 150 (CY150). If I pull the front brake the lever almost touches the grip. I have bled the hell out of this system and there was/is no air in it as far as I can tell. It's not spongy like air, it's spongy like cheap brake hose that is expanding.

I notice that about 50% of the lever travel is just to move the pads to the rotor (about 1 or 2mm), then it's spongy.

Assuming the spongyness is just the hose expanding, anyone have any tricks to eliminate that first 50% of travel before the brakes contact the rotor? I think if that wasn't there the brake would at least be usable. Right now it smashes my fingers on the grip before I get full braking.

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Remove caliper look at pads where they fit into the shim part - the top side of pads
The shim is like a spring pressing down pads to stop rattle
Make sure pads are not catching there
If you have rubber hose crimp it gently nearer master cylinder
Is it rock hard then? If yes issue is lower then crimped place
If no it's above the crimped place and prob master cylinder - 28-80¥
Calipers 45-90¥
I actually need a front disc but can't find on Taobao as I can't find the words to search with

Quote:

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Originally Posted by NZBrakelathes

Remove caliper look at pads where they fit into the shim part - the top side of pads
The shim is like a spring pressing down pads to stop rattle
Make sure pads are not catching there
If you have rubber hose crimp it gently nearer master cylinder
Is it rock hard then? If yes issue is lower then crimped place
If no it's above the crimped place and prob master cylinder - 28-80¥
Calipers 45-90¥
I actually need a front disc but can't find on Taobao as I can't find the words to search with

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You can find loads of stuff on MCM just need to look in the correct threads

to save you some time

http://www.mychinamoto.com/forums/sh...es-in-Mandarin

brake 煞車 / 剎車 sha che
brake caliper 卡鉗 ka qian
brake light 煞車燈 / 剎車燈 sha che deng
brake line 煞車油管 sha che you guan
brake pads 煞車皮 sha che pi
brake rotor 煞車碟盤 sha che die pan


What i done was to save all translation for parts on my Iphone
one day it could come in handy .....

Quote:

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Originally Posted by NZBrakelathes

...front disc but can't find on Taobao as I can't find the words to search...

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http://s.taobao.com/search?nofestiva...140929&olu=yes

Quote:

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Originally Posted by humanbeing

http://s.taobao.com/search?spm=a230r...3A1#J_relative

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Try again? That's just clothes and crap
I think my front caliper bracket or fork it self is bent as it makes a noise but I cannot see what's going
Being alone don't help I can't pull brake spin wheel and see the caliper all at the same time

I took the "ABS" thing off a long time ago and while it didn't fix the spongyness, it made the front brake grab a lot better. You don't need any extra bolts or anything to remove the "ABS", all the parts are there.

I think I might try a braided line at some point. I have taken the caliper apart and didn't see anything unusual but I guess it could still be messed up.

I wonder if there are yamaha/honda parts that could drop in as replacements. The line and master cylinder should be easy but I'm not sure about the caliper, it's probably a clone of a name brand though.