Brake Discs

As a newcomer to motor biking in general, I am not a tall up on maintenance issues although I do like to try everything myself. I passed my test last June, bought a SVS in January, but not really used it until now because of the poor weather and sports commitments. I took it for MOT last week and it failed on 3 counts: 1 - Loose footpeg/brake lever. 2 - Leaking rear brake caliper 3 - Contaminated brake discs.

The MOT man said to tighten up the footpeg, put a new washer on the caliper where the brake hose goes in, and clean the discs with wire wool.

After not finding a leak on the caliper, I changed the washers anyway and bled the brakes. I tightened up the footpeg and cleaned the brake discs with wire wool. This seemed to work, but then after comparing my bike to a friends SV, I realised that mine did indeed look contaminated with something. Another biker friend (not SV) suggested using Parafin as a cleaning aid which is suggested elsewhere in this site. He gave me some and I tried this but to no avail. I therefore have a bike sat in my garage, nice sunny weather but no MOT to ride it legally. Has anyone any suggestions on how to get this 'contamination' off my discs without me having to buy any new ones?

I would also just like to say that I have been reading articles on this site for a few weeks now and there appears to be a happy helpful community present. I am therefore confident that someone will come up with some answers to help me get back out on the open road.

Hello and welcome to the site..

Not too sure but brake cleaner may do it.... you could try Gunk (Halfords) that may work... other wise go back to it witht the parafin and wire brush and try harder!!

But what ever you do DO NOT use WD40!!!!!!!!!

Hey! Welcome !, What contamination exactly are you talking about?, does your disk only "looks" gray or is really greasy?
If its only a matter of appereance try harder with the brush. If it's greasy use a lot of soap and hot water. But i´m agree not using WD40.

It doesn't feel greasy, and the brakes work fine, On the Mot test sheet they had ticked brake performance, but failed it on brake condition. I originally cleaned with wire wool prior to the parafin, and on the inner of the disc,where there is no contact with the pads there was a hazy colour as though a grease was on it, like on a frying pan after it has been used but not cleaned. All that came off and it came back to a nice stainless steel colour, but after I had been out at the weekend, the greasy colour had come back to that area. I just haven't a clue what to do. I'll try and take a pic to post on here for you all to see.

I know a guy who works for a shop who takes there bikes to this particular test centre and said they are getting a bit funny, so maybe it might be worth just taking it somewhere else. But surely they should all test the same things???

Ok, but stay alert with that, it may be a drop of break fluid doing nasty thing, its very corrosive, and tends to hide quick.

id use brake cleaner,

or try a different MOT tester.

if its on the braking surface just ride around with the brakes on, anything that is on the braking surface will get burned off with the heat or worn away with the friction, never heard of brakes failing for being "contaminated" before

Just a thought, but is the greasy stuff being thrown out from over greased wheel bearings or a failed seal?

Are the discs discoloured? If so the brakes may have been binding.

Use brake cleaner for the discs, it's designed for the job and won't leave any kind of residue. Believe it or not, washing up liquid and very hot water is pretty good too, just rinse the parts of thoroughly afterwards.

Hope this helps

Rich

Thanks for all your comments, I'll give the brake cleaner thing a go I think. But I go on holiday Saturday so will be after then. WIll let you all know how I get on.