stiff/sticky rear brake

[scottomus0]

evening guys,


just a quick question.


not used my bike for over a week due to being away, left it out without its cover on (not end of world!)


got back on it other day and it soon came apparent that my back brake wasnt really working, felt really stiff putting pressure on it.


it was working at a slow pace, but felt as though i had to force it back up!


whats causing this? bit of rust due to weather?


many thanks

[Fuzzy]

I'm not a mechanic nor the most knowledgeable but I would hazard a guess and say, after a thorough check for obvious signs of something amiss, that an inspection & clean of the caliper might be a good starting point.

The calipers on the Fazers, especially the rear one, are prone to getting sticky pistons and are the most vulnerable at this time of year because of the lovely weather.

The way I do a "troubleshooter" is:

• Check for obvious signs of a problem. E.g. damage to anything in the system, from caliper, disc & hoses to the lever. If nothing is found:

Removal

• Take caliper off.
• Take pads out. Ensure the pads don't get any dirt, grease etc on them.
• Check condition of what is visible, paying attention to the pads, pistons and pins.

Pads

• Over worn? Replacement necessary? Are both pads wearing at the same rate? If not, this might point you towards the piston that is sticking. Ideally both pistons should push on the pads equally, the wear should reflect that.

Pistons

• The objective is to ensure the pistons are moving freely and give them a clean.

• If the pistons are dirty (probably will be), first carefully pump the lever to push them out a little so more of the pistons are exposed. Not too much or they'll pop out. Ideally the 2 pistons will move out at the same rate. If not, to entice a stubborn piston to move out, apply pressure to the one that is coming out more easily whilst pumping.
• Then get in there with a tooth brush and some soapy water or similar. Fairy liquid in warm water works for me, others use brake fluid or even WD40, that *might* damage the seals, seems to depend on who you speak to.
• Then I rub a little red rubber grease onto the pistons before pushing them back into the caliper (effort and time often required). Red rubber grease should help them move freely by means of lubrication, and form a barrier against potential corrosion. Not essential though.

Pins

• Inspect the 2 pins holding the pads in.
• Sometimes the pads can wear the pins down where they're in contact with them. If severe, replacement might be necessary.
• Otherwise, a quick clean, a scrub with scotchbrite or similar, and finally a coating of copper grease. This will help the pads slide on the pins when in use.

Refitting

• Refit the pads & pins after coating the reverse side of the pads (not the side that touches the disc!) with copper grease. Refit the caliper and carefully check everything. The brake pedal will need pumping several times to get the brakes working again.

If in doubt, take it to a pro, brakes are too important to get wrong.

[markbubble]

pistons might be stuck in bores a little due to weather/non service,maybe try freeing by use but watch if you 'stamp' on pedal in this weather!mine did same when i bought bike,its cheap to do a strip and rebuild with new seals etc if you can do work yourself but make sure you get pistons out before you undo and brake hose etc and go very carefull with banjo and bleed scres so they dont snap if your not sure leave to someone who knows wat there doing
 

[unfazed]

Most likely the brake lever pivot has seized. Spray the Brake lever pivot with WD40 and move it up and down a few times for the WD40 to do its stuff this should free it and if necessary remove it and grease it with lithium based grease. Common enough on bikes left out in the weather.

[darrsi]

WD40, then 3 in1 oil the brake lever pivot, EVERY MONTH, you'll be amazed how much better your brake works!

[red98]

as all of the above    my moneys on sticking pistons in the caliper,take the pads out grip one piston (i use water pump grips) and use the lever to ease one of the  the pistons out and check for corrosion and cleanness,push back in and then do the same with the other side parhaps working it in and out a few times