Please help

Air in the hydraulics and so you've tightened the adjuster up too far to compensate?

Thanks!

Robgvx wrote:

Air in the hydraulics and so you've tightened the adjuster up too far to compensate?

Okay thanks heaps! I’ll be workin on it tomorrow !!

Robgvx wrote:

Air in the hydraulics and so you've tightened the adjuster up too far to compensate?

Rory_Gow wrote:

Okay thanks heaps! I’ll be workin on it tomorrow !!

If you've got the brake pedal adjusted so there's no free play then ordinarily your back brake would be binding/locked on all the time. However if there's air in the system I've known people tighten the adjustment up to cure the soggy pedal and then if/when the air bleeds itself out it leaves the brake binding.

Another possibility, which I encountered years ago on a 1988 KX500 was that the rear brake calliper forks (the part that the outer pad rests against) would wear really quickly and hence the outside brake pad wasn't being held perpendicular/flat to the disc. This caused the brake pads to tilt and lock onto the pins rather like how a silicone/caulking gun works. That caused the brakes to bind, which in my case resulted in the brake fluid boiling. That caused no brakes. So, not the symptoms you are describing but worth checking. Just see if the outer pad has worn evenly or excessively more at the top. Never had that on any other bike since so maybe it was just that model.

Bleed your brakes ... I would just flush the whole system out with good quality motel or MAXIMA fluid... I had almost the same thing happen

As above, bleed and check brake pedal adjustment.
Would also be a good idea to remove the caliper from the caliper bracket. Clean the slide pins and the holes they sit in thoroughly and re grease. This will help the caliper to float and not rub on the disc as is spins. If your caliper can't float freely the pads may be rubbing on the disc, causing the heat build up and eventual full brake lock
Also check to make sure the disc isn't bent

Did you use a wrench and make an adjustment or add brake fluid just before this started or did it just start?

There is a tiny hole in the master cylinder that lets the pressure bleed off. It sounds like there is some debris blocking the hole. Flushing the system and not overfilling will probably take care of it

I once had a rock jam in the area between brake lever and case keeping the brake from releasing