Beta evo 2013 rear brake issue

[pancho247]

Hi, I’m looking for a bit of help. Not ridden my beta in nearly 2 years. I was going to enter a competition a few weeks ago and found my rear brake was not working. I bled it and unceased the calliper pistons, but didn’t see much difference, so I didn’t compete. Went green laning instead

I took it to my local shop he had a go and thought he fixed it. He bled it, did more unceasing of the calliper pistons and adjusted the rear brake pedal. I chucked the bike in the garage but didn’t try the brake. Stupid I know! Fast forward to now, I was gonna do a competition tomorrow, got the bike out and back brake is still rubbish, maybe marginally better. 
there looks plenty of meat on the pads. 
 

what else could the problem be?

thanks

Edited November 12, 2021 by pancho247

[totty79]

It could be a seal problem at either end, or contaminated pads, but I'd suggest ridding it before doing anything else. They tend to be weak after any work on them and they improve with a little use, the heat it up and chuck water trick on it can also make a big improvement. Pads need to be nearly new, the minimum thickness is less than half worn on many pads. If it doesn't improve you'll need to pop the pistons out a strip the master cylinder and rebuild/replace as required.

[ridgrunr]

One thing you might try is to ride the bike for a few minutes dragging the rear brake to heat up the pads and the disc, then dousing it with cold water. Might do it two or three times before you'll notice a difference. Seems that sometimes the disc or the pads get crud on them and this often brings them back to life.