Brakes?

[SoulRider]

hey peeps,

Well on saturday i noticed a small grinding noise coming from my front wheel, after inspection it turned out one of the four brake pads had worn to metal when the other three were about half left (all pretty much even and had loads left on them) Also the brake disc in question was very hot to touch.


Strange i know but we took the pads out and in trying to get the pistons to move only one moved forward and eventually slid out along with the seal, we drained the brake fluid reseated the seal and put the piston back in, after managing to lever all the other 3 pistons (did right side caliper as well) back in all the way we put the pads in, put them on the bike and after a few attempts bleed the system and got full working brakes again, great was good learning curve and was enjoyable doing it. (also learned to check all the pads).

However today and yesterday i noticed im still getting a kind of squeaking noise from the front wheel (first noticed about hour before grinding noise yesterday) when riding which only braking with the front seems to stop. The left brake disc gets very hot after a long run where as the other one gets warm.

Does this mean my brake disc is warped? Im guessing if so will need to be replaced before next mot. Also do the other 3 pistons need removing and reseating all the seals? How do you get the pistons out though as once one is out you cant pull the front brake to do it.

On a good note though since bleeding my calipers braking has improved . Cheers for any help you can provide
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[Finglonga]

Sounds like one of the pistons on the left is sticking. If the brakes pulsate slightly then the disc may be warped as rapid heat cycles can cause it. I would give the left calliper a good clean before replacing discs.
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F.Y.Y.F.F.

[instigator]

[SoulRider]

Cheers, so glad its not the discs, would love excuse to get wavy ones but just dont have that kind of money. Will remove the other pistom give it a good clean and reset it possibly next weekend as im not doing much.

Theres definatly no pulsating feeling when braking, feels nice and solid/smooth. These micro meters they expensive bits of kit?
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[Finglonga]

[Wafer_Thin_Ham]

If you spin the front wheel and look down the line of the disk you should be able to spot if it's warped as well.

I'd strip the other caliper and see.
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[Vincent]

[stinkwheel]

If you wanted to measure warpage, you'd need a tool called a dial guage. You'd need to hold the wheel spindle rigid, place the end of the guage on the disc and spin the wheel. The dial will measure any lateral deflection (very accurately). If it is outside the tolerance listed in the manual, it needs replacing.

Floating discs present another problem on account of being able to float from side to side.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Walloper]

Warped disc can cause the lever to feel slack till you pump fluid back into the caliper.
Pum pup the brake. Slowly Run the bike fwd to allow the disc to pass through the caliper. Stop with your feet. Try the lever. It should not travel any more than when you pumped it 1st time.
If you have lots of travel then a/the disc/s are pushing the pistons back in.

If the pistons are siezed you need to ensure they are not scored or coated with shit. Or you will knacker the seals.
Push the pistons out just enough to get Brake cleaner into them it will disolve most of the stuff.
If not resolved strip and clean/reseal.
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