FZS brake service

[Ricky]

Hi I am going to do a brake service on my FZS in the next few weeks,  I have the dot 4 and some red rubber  grease.
Never done a brake service  before, so any advice and pitfalls would  be appreciated.

[PieEater]

You should be replacing the seals I ordered mine from WeMoto, I used a wooden toothpick to get the old seals out as the metal is quite soft. I bought a set of brake piston pliers from Amazon and would suggest you invest in or borrow some as they will make the job a lot easier.

[Dustydes]

Lots of people get this bit wrong, but this is the procedure from Wurth.
And was used when I worked on cars.


Red rubber grease goes under the seal ONLY, or if you like in the groove the seal fits into.
Red rubber grease can cause binding if applied to pistons.
Most brakes start binding due to corrosion in this groove caused by the fluid being Hygroscopic the water in turn then cause corrosion which in turn pushes the seal out of the groove binding the brakes. When very very bad the piston will then bind on the seal and can pull it out of the groove, usually the dust seal goes first.
Red rubber grease helps stop the water thus the corrosion. 


The high temp grease should be applied to the pistons, slide pins and back of pads.
This will help when fitting pistons back in, less chance of picking up seal when pushing into place.
It also helps keep dirt out of the piston when in use by collecting dirt which is then wiped of the piston by the dust seal.


Remove callipers but not lines.
Remove pistons on bike first using the bikes hydraulics. Pump brakes to push pistons nearly all the way out, usually one or two will come out quicker than the others, hold these ones back say with a piece of wood and pump brake to push the others out.
When one or two have come out you can pull the others out. Dry first and try with your fingers. Don't use anything that can damage or mark the pistons, use piston pliers.
This bit can be the hardest part depending on the amount of binding if any. Note the brake fluid will pour out and you don't want it all over you bike, lots of paper towel.
Remove calipers from lines. Tie up high to stop them dripping
Inspect pistons for damage should be perfect.
 
Clean outside of brake and dry up any brake fluid left first away from build area.
Have a clean area to build in ready.
With a small sharp pick carefully prise old seals out of their retention groove without levering on the edges to do so, try not to slip and score bore.
With a suitable tool scrape any corrosion from the seal seats, again take your time and be careful. You should see aluminium and not white corrosion. make sure all is removed and to full depth.
Inspect bore for any damage, scrapes, scratches marks etc. should be perfect.
Again clean caliper and dry.


Assembly is fairly easy.
Red rubber grease in seal groove and on seals, doesn't need to be too much just enough to cover all exposed metal and seal. too much and it can stop seal going to full depth.
Fit piston seal in place first and using a suitable tool make sure it is pushed into groove to full depth. Smooth clean round piece of plastic can be used with a touch of the high temp grease or just a finger.
Then fit dust seal in same way.
Liberally coat piston with the high temp grease and push this into the bore, keep piston square to the bore and it should go in with firm pressure. Repeat
 
This sounds worse than it is in reality but it is your brakes.
Strip, clean, build.


If you are not confident or unsure about anything get professional help.
This is a guide only and should be carried out by professionals in brake systems.


Hope I haven't missed anything.   

[Ricky]

Thanks  Dustydes for the description.   PieEater says I should  be replacing the seals? Bike 05 with 20000 miles.
Just rang my local  Yamaha dealers and they want £175 for the seals and £175 for 4 piston. (hope I don't  need the pistons).
PieEater says he has used wemoto they want  about £45 for the front. On eBay plenty a lot cheaper but I dont have a lot of faith and my life is on the line.
I am absolutely  amazed at the Yamaha price, but  what to do, how do I know if they want changing? 

[Falcon 269]

Seals shouldn't need replacing, mate.  Check and clean the pistons as described and call it good. 

Unless you see something obviously amiss with the seals, or the calipers are really dirty, I wouldn't even disturb the seals during this routine clean. 

Copper grease pins and the backs of the pads as above and you'll be golden.

[VNA - BMW Wank]

 Haynes manual, Clymer manual?  There should be plenty of online guides and youtube videos to follow.  It’s straight forward.
Replace the seals?  I’d be wanting to determine the general condition of the callipers before jumping in and changing the seals.  My 35,000 mile 2004 model is still on the original rubber hoses and calliper seals.   Front brake is as good as the day it was new and the rear bake is just as crap as it ever was.
I like a thin coating of red rubber grease on my pistons after I have cleaned em.  Stops all the water and road shit getting to the piston, and as a result my brake piston look pretty much new.
For bleeding, I like this   https://www.amazon.co.uk/Draper-37316-Bleeding-Kit/dp/B0001K9TTM/ref=sr_1_1?ie=UTF8&qid=1503075683&sr=8-1&keywords=draper+brake+bleed     I just bleed a good bit though each year.

[Hedgetrimmer]

  the rear brake is just as crap as it ever was.

Surprised to hear this. I always put EBC standard pads in the rear, as opposed to the HH's I use in the front, because anything with more bite I've found to lock up the back too easily.

[PieEater]

The piston seals are subject to damage by constant repetitive heat cycles, dirt, brake fluid and degradation due to ageing which is why I would recommend replacing them if they haven't been done this far in the bikes life.


Apparently Triumph recommend replacing the seals every 2 years - http://www.triumphrat.net/sprint-forum/162386-brake-caliper-seals.html - which is a bit OTT IMHO.

[VNA - BMW Wank]

 It’s just dead, no feel.  If you give it a nice hard squeeze it’ll lock up.  Gotta be honest, I don’t use it anyway.  Really just give it a dab now and again to keep it working.
Pads?  I’ve always had the Yamaha OE ones on the front and can’t fault them.  Got EBC HH in rear, eventually replaced the pads that came with the bike cos they were falling apart.
 

[Dustydes]

I use EBC HH in front.
Rear ?????


As said if brakes are working fine then you can leave them alone.


Yours are not so will need investigating a bit further.


If your not replacing seals push pistons out a small way and clean the dirt off the piston and grease before pushing fully in to accept the new thicker pads. Leave old pads in so you don't pop pistons out too far, then remove pads and clean.
WhiteSpirit is a good cleaner and tooth brush.


Ideally they should be serviced every couple of years, but before you ask I do mine when I change pads but only check and grease. If any binding on pistons I replace seals. Your pistons should retract when on bike and master cylinder cover removed with firm pressure by hand and slide in smoothly, remember your master might/will overflow and can ruin paint.
As said red rubber not for pistons, you can get enough of both ( Red & High temp) for several services in the little packets of Worth for a few quid.
If you do go for new seals go with a well known company who have good quality control.


As for choice of rear pads I don't use back brake, but that's another story that can go on and on.


First rule is be safe and stop safe every thing else is for fun.

[PieEater]

........Remove pistons on bike first using the bikes hydraulics. Pump brakes to push pistons nearly all the way out, usually one or two will come out quicker than the others, hold these ones back say with a piece of wood and pump brake to push the others out.
When one or two have come out you can pull the others out. Dry first and try with your fingers. Don't use anything that can damage or mark the pistons, use piston pliers.........

Just to let clarify the above - there is only room to extract the pistons from one side of the calipers using the hydraulics to push them out, the pistons on the other side have to be held right back to allow the pistons you are trying to extract to come all the way out, hence why you need the piston pliers. You'll also need the piston pliers for the other caliper as when you come to do this you won't have any hydraulics.

[teecee90]

Interesting opinion on use of grease (copper or otherwise) on brakes ...

[PieEater]

Interesting opinion on use of grease (copper or otherwise) on brakes ...http://www.youtube.com/watch?v=uOwbSe2UhcY

I tried watching this but got seriously fed up with the bloke going over and over the same points about sintering that I couldn't take any more, a "giant rabbit shit"    . So if someone wants to post the relevant points I'd be appreciative.

[PaulSmith]

Interesting opinion on use of grease (copper or otherwise) on brakes ...http://www.youtube.com/watch?v=uOwbSe2UhcY

I tried watching this but got seriously fed up with the bloke going over and over the same points about sintering that I couldn't take any more, a "giant rabbit shit"    . So if someone wants to post the relevant points I'd be appreciative.

Agreed. I have seen this guy do 'Correction Videos' on other topics and he really doesn't get any better. If he has an interesting opinion, I haven't heard it yet.

[VNA - BMW Wank]

Interesting opinion on use of grease (copper or otherwise) on brakes ...

That fella is an absolute and total utter fud.  Not to mention 15 foccing minutes effing on about foc all.  No I didn't last long either.

I've always put a thin smear of copper ease on the back of my pads and on the retaining pins.  Stops the brakes squealing and allows you to get the pins back out again. 

As per photo I apply a thin smear of red rubber grease to the piston before pushing back in.  Red rubber grease is not just for the seals, it is suitable for use in the dry zones of vehicle hydralic brake systems which are prone to corrosion - ie and particulary so in this country - the pistons.  My seals are original and my pistons imaculate and the brakes work like new and my bike is often out in the wet.

[teecee90]

His presentation leaves a bit to be desired, but I actually thinks he knows his stuff. Greasing brake pads and pins is something I've always done based on received wisdom that it prevent seizure and squeeling.... but is it REALY necessary on modern(ish) braking systems? Maybe I'll run mine dry for a while and see if it makes any difference.

[PieEater]

Just taken my calipers off to give the pistons a clean. I had used red rubber grease on them for the first time the last time I serviced them and after seeing the amount of crap that this had attracted and caused to stick to the pistons I didn't bother this time, and probably won't again.

[NorthWestern]

I might use a bit of rubber grease on the seal as an assembly lube, very sparingly.  If you are putting it on the piston then it's a waste of time isn't it? The nature of the seal your pushing it into simply wipes it off leaving you with a build up of it on the end which, as pie says collects dirt etc.

Has anyone ever actually fixed squeeling brakes with coppaslip?  If they squeal then it usually means something isn't right.  I don't use it and never had issues. Ymmv.

[PaulSmith]

His presentation leaves a bit to be desired, but I actually thinks he knows his stuff. Greasing brake pads and pins is something I've always done based on received wisdom that it prevent seizure and squeeling.... but is it REALY necessary on modern(ish) braking systems? Maybe I'll run mine dry for a while and see if it makes any difference.

To be honest, I am not sure that he does know his stuff. I suspect that what he really, really likes is the sound of his own voice. I saw him in another video on Gearboxes that was just as long and almost as tedious where while the facts he used were not technically incorrect, he used them to imply something that was simply and verifiably wrong. In this case, after seven minutes of talking about sintering (which should have taken him 30 seconds) I gave up so I never got to hear his advice on copaslip.

Is it really necessary? No, of course not. Does it help? Yes it bloody well does. Ask anyone who forgot to copaslip their retaining pin and later had difficulty removing it. The difficulty comes from a build up of crap and corrosion that forms a solid seal. Do you want that same corrosion sealing your pads to your pistons? Preventing freedom of movement and probably affecting heat transfer? I don't, so even though I don't 'need' to, I will continue to use copaslip every time I service my brakes or change my pads.