Front Caliper problem

[Piki]

Hello there, I have a problem with my Front Caliper, the Front Wheel does not spin "freely", there is a constant "touch" with the pads. I adjust  it but nothing....It seems as If the Piston "not return" when I release the front brake, is the "seal piston" the problem? Any suggestion?
Thank you in advance.

[Bryanj]

Four possible problems in most common order
(1) pivot pin siezed
(2) Tiny hole in master cylinder blocked
(3) piston/seal and groove need thourough clean
(4) Flexible hose is blocked/collapsing

[mike the bike]

Remove the two M10 bolts holding the caliper onto the back part of the caliper and check that the arm that it was attached to swings freely.  if it doesn't, that's the problem.
Otherwise, the caliper seal may be worn, causing the piston to stick.  I suggest using the brake lever to pump the piston out prior to servicing.   Make sure the groove that the seal fits into is clear of crud.  A build up of crud causes the seal to wedge the piston.  Don't forget to put PTFE tape on the bleed nipple to prevent it from seizing.

[Piki]

Hello Bryanj and Mike thank you for  your answers,

The pivot pint work well, the Tiny Hole....how can I check it? Push the Brake and release and the brake fluid return to the master Cylinder?
I had change  the Brake fluid the last summer and no problem.....
I have steel hoses....
I think that the problem is the seal...
Thank you in advance.

[Johnwebley]

I had a similar problem,master cylinder clean,all holes open and clear,pivot smooth and easy,

it was the caliper piston seal,it had gone hard over the years,and stopped retracting the piston,
cost about £3 + p&p from DSS

fully cured the problem

[matthewmosse]

I have so far gotten away with pumping the piston out as far as I dare - about to the worn out pads position then cleaning with wd40 and a toothbrush, then pushing the piston back in with a vise or g clamp with soft jaws ( couple of bits of firewood) a few times if the brakes play up, plus greasing the swinging pivot etc. A modest ammout of copper grease over stuff to keep the rust at bay afterwards, remembering that any excess travelling to the pad surface would mean not very much brakes! And very often that is enough I found, at least on my bikes which were all weather commuters. Being a tad cautious, I leave further and more involved medling with brakes to a pro, but in 15 years only my wifes 250 nighthawk has needed more than the described treatment, most of those years, on my venerable cb500/4 sidecar outfit wherd this was needed every 6 months or so.