revtothelimit - motorbike forum

Been riding 46 years and never dreamt of cleaning disks. Always assumed the hard treatment they get would clean them.
But just lately the braking has lost it's edge. Changed pads but still same.
At Portimao the braking force wasn't always consistent. Just had to apply more pressure sometimes. I wasn't chasing lap times so let it go.

Just checked the front disks and they are covered in black crap. I thought the track use would have cleaned them ??

Anyway. What is this crap? Brake dust?

And best way to clean them? Taking wheel out tmrw to get new tyre fitted so will take the disks out. Can I soak them overnight in petrol?

Brake cleaner?

Spray them with brake cleaner and wipe off with a clean rag or strong tissue roll

weeksy wrote: Fri Nov 10, 2023 4:06 pmBrake cleaner?

I have some, but don't like using aerosols near brakes.

Because you might get it on the brakes?

That by definition is its job.

Spray onto a rag then wipe

weeksy wrote: Fri Nov 10, 2023 4:09 pm Because you might get it on the brakes?

Maybe. I'll try the cleaner

About the only thing that the black deposits can be is old (probably burnt) pad material. You've been using them too hard!

When you get the new tyre fitted ask if there's anywhere that can bead blast the rotors.That's the best way to remove contaminants and it also leaves a good surface for pads to bed into. And if the pads are looking the slightest bit second hand get some new ones.

mangocrazy wrote: Fri Nov 10, 2023 4:24 pm About the only thing that the black deposits can be is old (probably burnt) pad material. You've been using them too hard!

When you get the new tyre fitted ask if there's anywhere that can bead blast the rotors.That's the best way to remove contaminants and it also leaves a good surface for pads to bed into. And if the pads are looking the slightest bit second hand get some new ones.

I'll whip them off and deglaze them as well.

weeksy wrote: Fri Nov 10, 2023 4:06 pmBrake cleaner?

Handy gear for the garage,I use it for carb cleaning jets n' stuff,but not the rubber bits. It's an excellent degreaser.

Great for cleaning surfaces if you want to glue something.

Shortly after I first got it, I realised the front brakes on my fz6 had not done well by doing only 10k miles in 20 years.

Like you, I wasn't keen on spraying a load of brake clean all around the bike. The more so because that's never going to get the drillings clean.

I took the front discs and pads off it, and brought them to the kitchen sink. Lots of elbow grease, dish soap, a variety of stiff brushes, and a nozzle brush for the drillings got them clean again, and the braking was much improved. I did give them a final wipe with some brake clean and a rag, but by then there really wasn't anything left to remove.

I'd go as far as to say you're wasting your time if you don't have a nozzle brush, as there's no other good way to clean out the drillings.

If you've got a drill bit with the same (or very close) OD you could run that through them?

You can spray it all over the pads aswel, won't hurt.

KungFooBob wrote: Fri Nov 10, 2023 7:57 pm If you've got a drill bit with the same (or very close) OD you could run that through them?

Yeah . I was thinking that.

You should reaming them to a consistent size, it'll mean the disc is dynamically balanced and the brakes will be smoother as a result.

KungFooBob wrote: Fri Nov 10, 2023 7:57 pm If you've got a drill bit with the same (or very close) OD you could run that through them?

Hex drive brass or steel wire brush, reversible drill, you might need 3 or 4 of the brushes, but they're cheap as chips.

Skub wrote: Fri Nov 10, 2023 7:52 pm

weeksy wrote: Fri Nov 10, 2023 4:06 pmBrake cleaner?

Handy gear for the garage,I use it for carb cleaning jets n' stuff,but not the rubber bits. It's an excellent degreaser.

Great for cleaning surfaces if you want to glue something.

Why don't you use carb cleaner?

I don't think there is much difference between brake,cAarb and clutch cleaner.

cheb wrote: Fri Nov 10, 2023 8:49 pm You should reaming them to a consistent size, it'll mean the disc is dynamically balanced and the brakes will be smoother as a result.

Surely you've got to do them as a pair to maintain the twin plane balance?

I suspect David is right by the way, brake/clutch/carb cleaners are all just variations on the same volatile solvents.

10 points to skub too, thinking about proper cleaning before bonding I've got a 5 litre bottle (or had, used some obvs) of it I've used for brakes, but also loads of little nadgery bits covered in gunk. Aerosol is a marked up rip off IMO.

Le_Fromage_Grande wrote: Sat Nov 11, 2023 6:30 am

Skub wrote: Fri Nov 10, 2023 7:52 pm

weeksy wrote: Fri Nov 10, 2023 4:06 pmBrake cleaner?

Handy gear for the garage,I use it for carb cleaning jets n' stuff,but not the rubber bits. It's an excellent degreaser.

Great for cleaning surfaces if you want to glue something.

Why don't you use carb cleaner?

Probably convenience,the one can does lots of things. It's all kinda acetone isn't it?

KungFooBob wrote: Fri Nov 10, 2023 7:57 pm If you've got a drill bit with the same (or very close) OD you could run that through them?

Did that with wheel still in and got a lot of crap out. 95% of the shit is on the disk, so not too bothered about a tiny bit in the holes.

I'll look for a drill wire brush later though.