SPONGY BRAKES

[topchum]

I had to changes the front pads on my 92 600. After a lot of effort trying to push back one of the pistons, I ended up taking the caliper off, and persuading the piston back in with the wooden end of my hammer. Back on went the new pads, caliper back on and bled the system. Problem is now the brake is very spongy. I have bled it out a couple of times, but its still spongy. Am I doing something wrong? Is it a quirk of the system? Or have I bu****ed it up completely. There is no signs of fluid leakage? ANY HELP? ADVICE? WORDS OF WISDOM? A FIX !!!!! will be greatly appreciated.

Thanks for looking in

Cheers
ANDY

[pebbles]

did u have the fluid res cap off when u were
pushing the pistons back that could of made
pushing the piston back rather hard.
brakes spongy due to air in system perhaps
some is leaking past the piston due to seal
damage.or an air lock can form in the line but
unlikly ,let it settle over night try again tommorow
if there is no obvious sign of a leak take the
pads off again and see if there is any fluid
around the piston u are not to far away
if need be could pop up and have a look

[topchum]

I had to take the caliper completely off the bike, to put it on the garage floor. Bled it again tonight when I got in front work. Aint tried it since. No signs of fluid leakage at present. I will have another go when I get in from work tomorrow. If no joy, I may take your very kind offer up .. Cheers Pebbles

regards
Andy

[Ghoti]

Try strapping the lever tight to the hand grip overnight (I use a bungie), ie in the brakes on position.

Sometimes helps.

[General Gman]

Might be worth just cracking open the banjo bolt on the master cylinder - sometimes get a bit of air there.
Also, are you using new fluid ? if you've had fluid sat around for a while, it might be shot.
And try the Ghoti-tip - works a treat usually.

[topchum]

Cheers All,
Trying as we speaketh

Regards
Andy

[CD]

Also worth checking all of the pads are properly seated in the caliper and moving properly. If one is jamming it could also give the feeling of spongy brakes.

[topchum]

Cheers Dave, Just bled them again. Slight improvement (but only just) Checked the pads in the caliper OK...Brake lever now hard against the grip. Heres hoping then.

[Ghoti]

topchum said:

Cheers Dave, Just bled them again. Slight improvement (but only just) Checked the pads in the caliper OK...Brake lever now hard against the grip. Heres hoping then.

You're not following my instructions . I clearly said do it overnight!

Leave it for a couple of hours should do the trick. If you are not using your bike tonight, in a couple of hours, take the strap off, pump the brakes (you'll probably feel it better already by then) and re-apply the strap for the night.

[eliminator]

It's possible that the piston you had to force back in is covered on crap & is not moving as it should.

[topchum]

Just removed the dog lead from the lever .. seems like a good improvement. Have re-applied it, so heres hoping for the morning. If I come to sudden halt due to an immovable object (car, tree, wall) I know I have failed. Will let you all know tomorrow night either from A+E or from home.

Thanks to you all in my hours of need.

Andy

[topchum]

Well, I'm home in one piece. Brakes a lot better, but still a little on the spongy side. Tied the lead to the lever for the night, and then see how it is in the morning .. Will keep you posted.

Cheers

Andy

[CD]

Another thought... If the disc is worn it will take awhile for the pads to bed in. That can feel spongy until properly bedded in.