How do you clean your brakes???

GSmonkey

GSmonkey

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I'm ashamed to say I've been a keen biker for 8yrs now and done many many miles, but have never actually cleaned my brakes. Now having some degree of mechanical sympathy having seen the the shite accumulating on the bike over the last few months and with the large service intervals of the bike I'd like to have a pop at cleaning the brakes now.

Now I've never acutally taken any calipers off, changed pads or the like, so I'm new to all thinks 'brakey'.

Mouse put together a good guide on how to take off the pads etc. on the 1200GS, so I'm quite confident I could do this, but I'm a bit unsure of how to go about cleaning the pistons.

I was thinking of getting a toothbrush and some spray on 'brake cleaner' from halfords and just having a bash. I know you should press the brake levers to extend the pistons slightly, but don't know by how much. I'm afraid of poping the pistons out completely then having a right mess on my hands.

Any hints and tips (no matter how basic :D ) on how to go about the job??

Any pointers on what NOT to do would also be good to point out.

Thanks in advance.
 
I just either throw a bucket of water over them, having washed the bike or jet wash them. The mileage I do they aren't usually on the bike too long. I know I should clean them and stick some high melting point grease on the pin's but, just never get round to it. Having said that in 28 years of riding through winter I've never had a problem.
 
I was thinking of getting a toothbrush and some spray on 'brake cleaner' from halfords
Click to expand...

Yup - thats about it really. There's not much to it as long as you make sure you reassemble carefully.

You can squeeze the brake lever to push the pistons out a bit. It's not particularly sensitive but be a bit careful. If you do one piston at a time, you can squeeze them out enough to enable them to be twisted in their sockets - making it easier to clean and grease them properly. Do try not to pull them right out though while your scrubbing them - otherwise you'll spill a load of brake fluid all over your nice rims and tires and end up having to spend ages bleeding the whole bloody sysytem again! A *friend* of mine has just done exactly this!! Arrrgggghhhhh!!!! :mad:
 
I'm not familiar with discs brakes on oilheads but on Honda Pan Europeans unless the pistons are cleaned every twelve months or so, they will run the risk of seizing. With the aid of a Haynes Workshop Manual, remove the caliper. With a years road dirt and brake dust, the calipers will be in a right state. DO NOT allow the calipers to dangle as this will put a strain on the flexible brake hose. After removing the brake pads, pins, anti-squeal shims, etc, spray Halfords brake cleaner around the caliper and clean everything up. Now using the front brake lever ease the pistons out say 1/4", enough to reveal to build up of dirt on the sides of the pistons. DO NOT allow the pistons to either come out to far or to fly out. If one piston is seized, apply a G-clamp to the others, then use the brake lever to force the reluctant one out a short way. (Frankly, if they've not been dismantled and thoroughly cleaned for a few years, it's no big deal to get the pistons out completely and do a proper job cleaning the bores and pistons. smear brake fluid in the bores and pistons and ease them back into the bores with thumb pressure. You may need to crack open the bleed nipple to allow you to do this. When fitting the cleaned up brake pads and anti-squeal shims if fitted, apply a film of Copaslip to their backs. This will also prevent squealing later on. Bleed the brakes.

It's not a difficult job, although I've grossly simplified it. Have a go and it will be reassuring for you to know your brakes are top notch.

*I suppose in the PC world we live in, I should add that if you follow this advice and something goes wrong, .........
 
[American type disclaimer] If it goes t*ts up and you crash because of info written here, s'not my fault[/American type disclaimer]

I haven't stripped a set of BMW brakes yet, but generally speaking here’s what I do. Remove caliper and remove pads from caliper. Clean all edges and the back of the pads. Clean all caliper pins and springs etc. Whilst watching the pistons slowly and gently apply pressure to brake lever and watch pads move 1-2mm. They don’t normally move in unison. If one is stuck wedge something between the others and pump piston forward. To clarify, you need the travel limited for the free moving ones or they will pop out.

Once you have the pistons moved a couple of mm clean all the caliper with brake cleaner or alloy wheel cleaner and wash off with clean hot water thoroughly. Lightly wipe the pistons with clean fresh brake fluid and push them back in a few mm. You may need to remove the reservoir top to do this, but remember if pushing the pads back you push the fluid back up the brake lines!! If it spills it eats paint!!! You have been warned!!!

Ok pistons back in and moving freely now? Pump and work the pistons back and forth a few times. Now smear the back of the pads with copper slip grease and also apply thinly on any surfaces the pads contact with in the caliper body. Also lightly smear copperslip to the pad retaining pins. Refit pads and then refit calipers. Check fluid level is ok. Check discs are clean, better yet wipe with brake cleaner to make sure.

Now pump the brake lever to push pads back out to where they should be BEFORE riding or pushing the bike anywhere! Check brakes bite and release ok. You're done.

Remember brake fluid is hygroscopic, which if you don’t know, it means it absorbs moisture from the atmosphere, so don’t leave the reservoir lid off overnight or anything. FWIW< I would advise replacing brake fluid annually.
 
All reasonable advice so far I think :)

I never use brake cleaning fluid. I find the dirt usually comes off easily enough by using a dry toothbrush. If you need to clean a stubborn piston, pump it out slightly and use a thin strip of rag - wrap the rag all the way round the piston's circumference and rub back and forth. If the dirt still won't come off, I use a tiny amount of brake fluid.

I wouldn't use clamps on the piston either. The plastic pistons in the GS have plastic inserts in the centre which have been known to break. If you need to stop a pair of pistons moving, place a bit of wood between them. In my experience, if, to hold a piston in place or push it back in, you need more force than you can apply with your fingers, your caliper is seriously knackered.

If you need to support a brake caliper, hook a bungee cord through one of the mounting points and attach the other end to the handlebars or something convenient. Although to be honest I seriously doubt you'd damage a braided steel brake line in any way by hanging the weight of a brake caliper form it.

On ABS equipped bikes, be careful when pushing pistons back into the caliper. Push them slowly and gently. Again, if you need more force than you can apply with your fingers, something is wrong.

Remember that on servo equipped bikes (is this right? I might mean ABS), the hydraulic circuit to the caliper is not connected to the fluid reservoir. So you don't need to remove the lid from the reservoir when pushing the pistons back in.
 
Cheers guys, you've clarified a few points for me there.

So the only lubing to do is the back of the pads & pins with copperslip and the pistons themselves with brake fluid.

Sounds good to me.....I'll give it a crack.

Next post will be......shit my pistons have come out, how do I bleed the brakes???:D
 
Extend pistons???????

Monkey,

I do not agree that the piston should be extended from the caliper for cleaning unless it is "sticky". Minute particles of dirt scrubbed into the piston surface will slowly damage the seal.

Just use a spray can of brake cleaner all over the caliper and lastly around the piston bore. The seal keeps fluid pressure in and muck out- I see no point using brake fluid as a lubricant on the atmospheric side of the seals as it will absorb water and make matters worse- if the pads are worn and so the pistons extended, and more area exposed to dirt, they need to be very carefully cleaned before pushing back to accept new, thicker, pads. The best lubricant is supplied by (eg)ATE with caliper reconditioning kits. It is a high temperature silicone grease which will not damage the seals. Hydrocarbon grease on pistons or in piston bores is hazardous as it WILL swell the seals causing seizure and/or brake failure. It may also melt and end up on the pads, brakes can attain 600 celcius even on a road bike, so HMP copper or nickel based is best.

The piston boots on most car calipers solve a lot of this, but space on a bike is the problem and our access is better. So we can give them a blast with brake cleaner any time without a strip down.
 
I agree with Terry about the grease. I wasn't suggesting using brake fluid to lubricate the pistons, merely to loosen stubborn dirt if required.

I usually give the pistons a very thin coat of red brake grease before pushing them back in.
 
Well there you go, each and everone of us has a slightly different method of cleaning the brakes, and I don't suppose any of them are far wrong (If there is such a thing as 'right'). Personally I apply a thin film of Copaslip to the pistons during my annual clean up, and no harm so far.

I also feel happier when I can press the pistons in with thumb pressure, and when the Brembo 4-pot caliper (for my R100GS-PD)arrived from Motorworks, I couldn't budge them. It wasn't until I GENTLY used a G-clamp that they moved pretty well, so I'll put their stickiness down to being on a shelf for a few months.

It's easy to get a bit anal about things such as brakes, oil, tyres and so on, but the cardinal rule of thumb with brakes is 'Cleanliness is next to Godliness'.

Ride safely...
 
Is the brake cleaner stuff nasty, or am I ok to spray at will?? Never knew you could use the cleaner with the caliper installed, thought it might contaminate the pads, or does brake cleaner NOT contaminate pads??

So the lube for the pistons should be either copperslip or nickel based.....got some copperslip but I'll have a look round Halfords for some other (non hydrocarbon) grease. Silicon grease any good??
 
GSmonkey said:
Is the brake cleaner stuff nasty, or am I ok to spray at will?? Never knew you could use the cleaner with the caliper installed, thought it might contaminate the pads, or does brake cleaner NOT contaminate pads??

So the lube for the pistons should be either copperslip or nickel based.....got some copperslip but I'll have a look round Halfords for some other (non hydrocarbon) grease. Silicon grease any good??
Click to expand...

Monkey,

Brake cleaning fluid is like dry cleaning fluid, it is not a hydrocarbon in the sense of being a lubricant. You can spray it all over the pads and it will evaporate instantly leaving no harmful residue. Of course it will dissolve grease so unless you wash the oily stuff onto the pads with it you have no worries.

Apologies if I contradict anyone, but copaslip(hydrocarbon based grease right?) on pistons on the caliper side of the seals is a very risky thing, and even in contact with the atmospheric side of the seals is potentially dangerous. There are two reasons. First is that any hydrocarbon in contact with normal hydraulic seal rubber can and will cause it to swell. If in the presence of hot brake fluid multiply by n^10. Second, any HC inside the caliper seals in contact with brake fluid will release HC gases. This is what you have with air in the brakes-no brakes.

And just because it did not happen to someone else is a guarantee that it will happen to you or me. I do not do DIY brain surgery and do not recommend brake work if the rules are unclear.

If in doubt go buy "Tune to Win" by Carroll Smith. He was the guy who did all the Ford Le Man stuff etc and wrote the manual.

Terry
 
Irrespective of the properties of hydrocarbon based grease (about which Terry knows far more than me), copper grease is clearly not the correct stuff to use on the pistons. It contains particles of metallic copper, which are intended to lubricate a metal / metal interface - not a nylon / rubber interface as in a brake piston and seal.

Monkey - ask at your local bike shop. Brake seal kits usually come with a small sachet of red brake grease. They may have some lying around that they coud give you. One of these sachets is enough to service a dozen calipers, you need that little of the stuff.
 
I reckon it's a bit of a moot point anyway. I used (or tried to) some Castrol Red Rubber grease on the pistons. But a) its very difficult to get the stuff on, fiddly and messy and also it won't adhere properly as the residue of brake fluid stops it 'sticking' and b) it all just slides off when you push the pistons back in anyway!! :mad:

I personally won't bother using the stuff again, I think I'll just make sure the pots are lubricated with brake fluid and not 'dry' before i push 'em back in their 'oles... Tiny dab of Copper Slip on the back of the pads where they meet the pistons and job done!
 
Just to say thanks for all the advice guys.

Finally got round to cleaning the caliper and changing the pads on the back and cleaning the calipers at the front. Loads of crud in the calipers after such a salty winter so a very rewarding job:)
 
Where can I buy this red grease to slap on the pistons. Just stripped the brakes on the back up bike (HONDA CB1 400), I put copper grease on the pistons, as nothing else was to hand.

Tip for you, learnt the hard way. If the pads are siezed onto the disc, don't do as I did. Try to force them back with a screwdriver, just bent the pad.
 
Having just cleaned my brakes using some of the tips above:

Blast away with brake cleaner, followed by scrubbing with brake fluid and toothbrush, with a finla brake cleaner flush to disperse the DOT 4.

I also found quite a handy way of cleaning the backs of the pistons, without turning them. I read that one of you fed a strip of rag round the back of the piston to clean it. Using this principal, i had an idea of what els I could use: Velcro!!

I bought some a while back to fix my leathers and had some left over: cut the edges away so the bristly bit is right up to the edge, feed it round the back of partly exposed pistons, once you have spread a bit of DOT 4 round, and scrub back and forth.

It abrasive enough to remove caked-on crud, but its nowhere near hard enough to be abrasive on the piston wall. Brakes are still giving me trouble, but that's another story
 
Nippy Normans supply Touratech, Wunderlich, Desert Fox and many other makes of accessories.
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