Help! I have just bought a mountain bike with disc brakes?

Question

But I sprayed the chain and the brakes with WD40 and now the brakes make a screeching noise everytime I brake. I have tried wiping the pads with alcohol but it has not worked. Can anyone give me suggestions on how to stop the screeching please. (This question is on behalf of my son)

Answer 1

Regular multi-purpose oil should only be used on chains - WD40 is a degreasing solvent, and although it has lubricating properties, it will dissolve the factory grease on the chain and replace it with thinner fluids that create excessive wear between gear and link. As for the brakepads, add a dose of methylated spirits to a piece of kitchen roll, hold this against the rim of the brake disc and spin the wheel while lightly pressing the brake. Allow the methylate spirits to dissolve the WD40 enough, about two-three applications, spinning for a minute each time. Then a new piece of kitchen roll soaked with water and repeat for three minutes or so. Allow the brakes to dry naturally. Beware of getting methylated spirits on the tyre, as it may cause degradation depending on the tyre's plasticity.

Answer 2

Don't forget to clean the rims, too.

The screech might not be caused by the WD-40. Brakes need to be toed-in slightly to prevent squealing. The better and stiffer the brake calipers are, the less they need it, but I've never seen brakes that didn't need at least a minimal amount of toe-in.

Answer 3

just wash the disc and pads with de greaser the noise will go just go for a ride and on your ride through some heavy braking in, also for future reference don't use wd40 on chains it burns through grease it may solve a squeak, but  tests show having no lube what so ever on the chain will still last longer then one with wd40 on, i used it for years though when i stopped i stopped having problem's, i would wash it of with soapy water and an old tooth brush or bike brush wipe dry re apply   3 in 1 bike lube its cheaper then wd40 theres some great videos on you tube on mountain bike maintenance.

Answer 4

It should go away after a wile i think there might still be wd40 on the pads. if it doesn't go away then replace the pads

Answer 5

Go to a motor spares shop and buy a can of brake de-greaser spray.