Rear Brake

[Bofh5]

Hi
I'm trying to diagnose the problem with my back brake.
Everything was fine until i replaced the pads and now i have very little to non existant braking.

I've bled it the through with new brake fluid and can't see any air coming out. When i press down on the pedal the caliper moves but i can stand on the pedal and theres still not enough pressure to lock the rear wheel.

As far as i can tell there are no leaks so was wondering if its the pads themselves. They are standard EBC pads. Is it possible to have a dodgy set of pads thats just wont grip the disc no matter how much pressure is applied?

As i can't see any leaks i dont want to strip the caliper / master cylinder but this is my next step unless anyone can suggest another cause.

Thanks
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(L)users...Disk space is to good for them.

Bikes: Honda 50 / CB125-TDC / 93 CBR600 F2 (Stolen & Trashed) / 2001 SP-1 (Sold) / 95 CBR600 F3

[Itchy]

Bleed them once more? , in that when I bleed my brakes on the ciber all the largish bubbles are dispensed of quite quickly , but you have many many tiny bubbles sort of like you get in cans of coke , these do affect the pressure. To save on pumping tons of your fluid out do up the nipple pump the brake pedal 5-10 times then hold THEN undo the bleed nipple.

Take the caliper off and give it a shake, this should get any trapped air out.

I think pads are a red herring in that even worn down to the metal pad backing my brakes can and will lock the wheels (I ran my pads so low on the NTV once they were bare metal no friction material).

If you've cleaned the piston you can also push with your thumbs the piston in and it should force air and fluid back to the master cylinder.
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[Bofh5]

Thanks i'll give that a go.
If the seals were going and air was getting in then i'm guessing fluid would be leaking out and be fairly obvious right ?
Cheers
____________________
(L)users...Disk space is to good for them.

Bikes: Honda 50 / CB125-TDC / 93 CBR600 F2 (Stolen & Trashed) / 2001 SP-1 (Sold) / 95 CBR600 F3

[Bofh5]

ok bit weird !

took the calliper off and raised it to see if there was any air in the line.
Put a piece of wood for the piston to press against and pressed the pedal.
Bingo all works fine the piston leaving a mark on the wood so plenty of pressure there.
Cleaned it up put back on and same crap again...pressures gone.

So i know everything is working ok from my test so any ideas what it could be?

<pulls hair out>
____________________
(L)users...Disk space is to good for them.

Bikes: Honda 50 / CB125-TDC / 93 CBR600 F2 (Stolen & Trashed) / 2001 SP-1 (Sold) / 95 CBR600 F3

[clancy]

have the pads been worn in yet, or are they straight out of the packet?

leigh.
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KLX 300r

[Bofh5]

Well worn in
This is driving me nuts...
Looks like a complete overhaul just to be sure
____________________
(L)users...Disk space is to good for them.

Bikes: Honda 50 / CB125-TDC / 93 CBR600 F2 (Stolen & Trashed) / 2001 SP-1 (Sold) / 95 CBR600 F3

[clancy]

seems like youve checked most things :S
how strange.

leigh
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KLX 300r

[Bofh5]

Well i adjusted the pedal travel and now it kinda works. I'm beginning to suspect crap pads.

Will do for now and i'll get some new pads and try them.
Thanks all for the advice.
Cheers
____________________
(L)users...Disk space is to good for them.

Bikes: Honda 50 / CB125-TDC / 93 CBR600 F2 (Stolen & Trashed) / 2001 SP-1 (Sold) / 95 CBR600 F3

[G]