Pitted disk.

[Clem]

Gave the brakes their post winter strip and clean last month followed by a good all over wash down.

Checking the bike over today and I noticed that the outer side of the LH disk has pitted where the pads have been in contact over the week.

Can a combination of Wurth Brake Cleaner and water do this within a week?
Or is it something that I've missed previously?

I'm sure it wasn't there last week when I stripped the calipers off and the straight profile (across the disk surface, rather than in the directon of rotation) seems to show that the pitting has happened where the pad has been sitting on the disk..

Never seen it happed like this before, fortunately it's only on one disk face so we'll see how a good run out to Whitby tomorrow effects it.

 

[ebbo]

The stainless steel your discs are made from is not totally immune from rusting, but it is normally very resistant. Myself, I wouldn’t put the bike away with wet discs and pads as I’ve seen this sort of corrosion before, but I have to say, not as bad as that seems to be.

Makes me wonder how active the ingredients of the Wurth Brake Disc cleaner were, I suppose that soaked in to the pads first when you were cleaning, but wasn’t completely washed out during rinsing?

 

[Clem]

The brakes and pads did get a good clean with the brake cleaner.

I've checked the Wurth MSDS and the cleaner is Propan-2-ol and Naptha, neither of which should cause significant rusting on stainless.

I can only summise that a combination of brake dust, salts and the water from the washing has collected in the pad grooves and attacked the disk.

You learn something new (and potentially sxpensive) every day!

 

[ELIMINATOR]

I wouldn’t put the bike away with wet discs and pads

Blow dry yours do, you after coming from a wet ride

 

[Packer]

Factory discs are very prone to pitting. I had at least two sets under warranty. I'm on Steptoe discs at the moment and although theysuffer from a slight high spot they seem more resistant to pitting.

 

[ebbo]

Blow dry yours do, you after coming from a wet ride

I was meaning more in terms of washing it and putting it away wet, in normal use if its raining the brakes tend to dry them out...

 

[motobiker]

I have never seen this on either of my bikes. despite the fact they both have always lived outside. this one and its predecessor. and are/were ridden in all weathers often parked up ringing wet. Occasionally I see a very light coating of rust. but whether this is the discs themselves or some kind of residue from the pads - I don't know.

pitting? absolutely never. I never use 'brake cleaner' apart from the stuff that evaporates very quickly. I call it 'dry cleaner' but has no action beyond rinsing out any detritus and then evaporating with no residue.

Seems obvious to me the 'Wurth' cleaner used isn't 'Worth' using and is best avoided much like you'ld avoid people with plague or the 'watchtower'

 

[alimey4u2]

Brake dust is highly corrosive, nothing to do with Wurth, you may have had some trapped there together with an electolyte, IE tap water...