I have a CBR 125 with 12k on the clock, when I brought the bike it seemed to be fine, but I guess I didn’t check all over. Once I got it home and passed my CBT, i notice that the front wheel was not moving freely. I’d removed the brake and found that one of the piston had seized.
I brought new seals etc… and rep-built the caliper, bike was sorted and has been since since.
Two year after the wheel has started to stick again, to the point where I can’t even move the bike without force.
Yes, bike callipers need cleaning regularly. They are more exposed than car callipers so subject to more corrosive s**t.
Most times it’s just an “external” clean, so no new seals/re build.
Just take the calliper off (still connected to the hydraulics), take out the pads, stick a piece of wood/plastic/metal/whatever in between the pistons a bit thicker than the disc plus both pad back plates . Then get in there with the old tooth brush and brake cleaner.
But in your case with the pistons sticking, it sounds like the full banana of proper clean/new seals/new fluid.
Sorry to bring bad news but if you want the pleasure, you have to put up with the pain every two or three years.
Oh. When you’ve done all that, do make sure that the master cylinder is working properly and not the cause of the problem.
Just be happy that you don’t have a set of Tokico 6 pots … they need stripping at least twice a year and a proper clean monthly.
And a set of seals costs the thick end of £80.
Just dont “lube” the pistons with anything. Pertolleum based stuff (wd40/greases in copper grease) swells/rots the seals. (think ACF50 is ok though, not sure)
I’m going to get hold of some silicon grease for reassembly when I rebuild mine.
Someone recommended clearning the pistons (during rebuild) with autosol.
The CBR F’s calipers are nicely coated inside but the ones on my old Bros needed the grooves the seal fit into cleared of some gack, used a bamboo skewer.
There is a sort of fabled product out there know both as “rubber grease” and “red grease”.
Was once marketed by Girling, in tubes, and cost pennies. Since last month, I’m the proud owner of a very small tub of this stuff for just £7:45. (WTF?)
Turns out to be vegetable based grease so a drop of organic margarine for a penny or so would seem to be reasonable substitute for a brake rebuild.
