2010 Rancher 420 Front Brake Issue

[DGBear]

My front brakes started dragging and the lever travel was minimal. I bled them and topped off the fluid reservoir and they worked great for a while and now the problem has returned. I'm thinking that a piston may be sticking. Any thoughts on this problem?

[Mech]

If it's only one wheel then it may be a piston sticking or it may be the hose to that wheel. Undo a brake bleeder and see if they free up, if they do, it's not the caliper pistons. If only one side frees up then the other side has a blocked hose going to it's wheel. If they both free up then pump the brakes till they start dragging again then undo the hose up at the master cylinder and see if that also releases them. If undoing the hose there doesn't release the brakes then you have a blocked hose going from the bars to the frame.

The hoses can get blocked or get a flap of rubber that only lets fluid go one way. The master cylinder applies hundreds of pounds of pressure and forces fluid through a blockage, but the pistons only rely on the flexing of their rubber seals to push the piston and fluid back once you let the brakes off and it's not strong enough to fully return the pistons if the hose's partially blocked.

[DGBear]

Thanks!!