New brake caliper piston seals - which side is inwards/outwards?

[MrMogensen]

As title mentions I am in the middle of installing new brake piston seals (have never been done before and had to drain fluid anyways due to new ABM steel-braded brakelines so I might aswell do the whole chabang.
I removed the old seals a little to quickly before I noticed which side was inside/outside on the outer ring. One edge is rounded and the other edge is sharper. I know this design is intented to scrape the sides of the pistions when they are forced outwards to contain brake fluid inside the caliper.
I think I can feel the correct position when using my finger. I just want to be a little more certain

Searched the FZ6 Service Manual without any luck. Loads and loads of pages about calipers, brake piston seals etc. but just nothing as detailed as this.

 

[Gelvatron]

As title mentions I am in the middle of installing new brake piston seals (have never been done before and had to drain fluid anyways due to new ABM steel-braded brakelines so I might aswell do the whole chabang.
I removed the old seals a little to quickly before I noticed which side was inside/outside on the outer ring. One edge is rounded and the other edge is sharper. I know this design is intented to scrape the sides of the pistions when they are forced outwards to contain brake fluid inside the caliper.
I think I can feel the correct position when using my finger. I just want to be a little more certain

Searched the FZ6 Service Manual without any luck. Loads and loads of pages about calipers, brake piston seals etc. but just nothing as detailed as this.

usually the seal is a square cut o-ring and has no up or down, id check the techmanual but its at my uncles house

its basicly a square o-ring and when you apply the brake the piston moves out stretching the seal and the rubber gives to the hydraulic pressure once you release the rubbers elasticity brings the piston back just enough to let the pads move freely

i hope this helps assuming your mid instalation and want to finish asap

make sure to check the pitons for any imperfections, burs scratches rust etc... lube all the parts with NEW Brake fluid not even a bottle thats been on your shelf for a few weeks, as brake fluid collects moisture through plastic bottles(yes they have a shelf life)

lube seals and piston and be careful not to damage the seal on insertion

 

[MrMogensen]

There are 2 different o-rings per piston.

The square one (as you mention) has no inside/outside - so no problem there!

The outer more slim o-ring however has the "scraping" ability... with rounded edge one one side and sharper edge on the other side.

 

[Gelvatron]

There are 2 different o-rings per piston.

The square one (as you mention) has no inside/outside - so no problem there!

The outer more slim o-ring however has the "scraping" ability... with rounded edge one one side and sharper edge on the other side.

i have not done this on my bike yet so i didn't know that sorry for the miss information,

Perhaps you only took one side off and can look at the other?

other wise i am of no help to you sir. good luck though

 

[MrMogensen]

i have not done this on my bike yet so i didn't know that sorry for the miss information,

Perhaps you only took one side off and can look at the other?

other wise i am of no help to you sir. good luck though

Of course I was a dumba** and disassembled both sides before noticing.
The rear single piston brake also has dual o-ring but both of these are square.

The o-rings are original Yamaha parts.

I have a car and live near a bus/train station so luckily I am not in a hurry

Gelvatron you still get a couple of thanks for lightspeed posting

 

[FinalImpact]

Likewise, mine have not been out either. I suspect close examination of the used seals should show a little discoloration of dirt and dust on the outer edge indicating which way it went..
Let me ask this, the confusion is not that the seal is rolled inside out, its that the ID of the o-ring has a tapered ridge. I'm going to say the ridge (smaller ID) goes outward. But look for discoloration on the old seals.

 

[motojoe122]

I found this, it's not the same caliper we have but it shows which direction the seals go.[ame=http://www.youtube.com/watch?v=HYy-vPLmL0E]"How to" fit new brake caliper seals on your motorbike/motorcycle - YouTube[/ame]

 

[TownsendsFJR1300]

I did both my 4 pot 07 fronts and 04 FJR fronts, (their the same). On both bikes, all the edges were square on ALL the seals. I have not done an S1, dual piston set up.

BTW, the larger seal is the actual oil seal, the smaller is the dust seal. This goes for both the larger piston as well as the smaller piston.

I checked both Yamaha manuals as well (S1 and S2) and there's nothing posted.

If you didn't already take the other side apart, obviously look at that or look for crud built up on the DUST seal(as Randy stated), that'll tell you that side faces outward. Something else to examine is if the piston slot (for the dust seal) is square inside (should be). If not, and the piston is beveled, that's your answer, you may have to turn that dust seal inside out (kinda doubt it).

If none of that pans out, you'll find the pistons fit very tight (even lubed with brake fluid) and care needs to be taken when pushing the pistons back in, that their going in EXACTLY STRAIGHT.

I don't think it'll make a big difference one way or the other (its not going to leak, the oil seal takes care of that).

If I was in your shoes, I'd put the rounded edge facing outward, only for the ease of assembly. Once its together, the piston will ONLY start coming outwards with age as the pads wear.

Make sure you put brake lube on the slider pins so the caliper will easily center itself. It does tend to crud up and stick.

 

[MrMogensen]

On the video at 4:15 it's seen that the thin o-ring is not square (can't tell if it's rounded on both sides or not though).
Zero discoloration anywhere - so yes the pistons has a very tight fit so it shouldn't matter much. I am going to put them in with rounded edge outwards

BTW: Along with the set came a tiny plastic bag with some reddish thick stuff. Is that just some kind of brake grease for lubing the moving parts or should I use the intended brake fluid for everything instead?

 

[DavesFZ]

I put brake fluid on the pistons/seals only. Everything not in direct contact with brake fluid during operation I lube with that sticky brake lube. Make sure you put brake lube on all the slider pins and the backs of the pads to prevent squeaks. Keep that brake cleaner handy to clean the lube off your fingers.

Eta: if that red sticky stuff came with the seals, it is probably brake lube. If you aren't sure, go to the autoparts store and get some Permatex brake lubricant. A small tube will last several lifetimes.

 

[TownsendsFJR1300]

On the video at 4:15 it's seen that the thin o-ring is not square (can't tell if it's rounded on both sides or not though).
Zero discoloration anywhere - so yes the pistons has a very tight fit so it shouldn't matter much. I am going to put them in with rounded edge outwards

BTW: Along with the set came a tiny plastic bag with some reddish thick stuff. Is that just some kind of brake grease for lubing the moving parts or should I use the intended brake fluid for everything instead?

The pink squares are indeed, brake grease. My local shop (very knowledgeable BTW) the grease is for the seals, slider, etc.

The one time I used Permatex, brake specific grease (specificially designed to be used on the piston/seals) it assembled a little easier. That was the time I just cleaned and re-used the old seals which eventually started sticking again about 8 months later.

This last time, when I actually replaced ALL the seals (4 pots on the 07, each side), I used brake fluid only on the seals.

As noted above, the fresh rubber is what actually pulls the pistons back when the brake is NOT applied. I found using the brake grease on the pistons also liked to attract alot more crap (as it is super sticky).

The front wheel still has about "4.5 free spins" which is way longer than it ever was (7 months, 2,000 miles now). I do blow brake dust out of the calipers and discs maybe once a month (no dissassembly) too.

As for the use of the grease, besides putting a thin coat on the retainer pin, clean real good and re-grease the main bolts (that are smooth so the caliper slides and centers itself) as well as inside the rubber dust boot.

BTW, I think you made the right decision putting that rounded edge outwards as it will be tight going back together.

Should it be extremly difficult re-assembling the pistons into the caliper, you can put just a little bit on the seals, it won't hurt anything.

Make sure the hollow end of the pistons are visable once assembled.

:thumbup:

 

[Circle]

Ditto with Townie above.

Rebuilt my calipers 2 days ago on my '04. 1st time and haven't stacked it yet (But bleeding was a biarch! - Painted the calipers also, by that's another story)

With the smaller seal, keep the rounded edge pointing into the middle of the bore on the outermost groove.(This is the seal which will be closest to the brake pad)

The larger seal is pretty self explanatory - I'm certain its the same type of edge (straight) in the inner or outer circumference.

(Hmm reread the post - would be better with pictures... or mime. But its a bit of a confusing read, sorry! I'll take a look to see if I took any pictures...)

Enjoy your new brakes!

 

[hk_fz6_05]

just did this on mine - used the pink stuf on the pistons in a thin coat and that made things a lot easier. also didn't notice which way the smaller seals went in - I left them in the config they were in from factory but I seem to recall a very straight edge all the way from the top of the caliper to the bottom, so I'd say straight edge out.

If this is still an issue I'm pretty sure I have pics to explain or you can come visit :BLAA:

 

[TownsendsFJR1300]

Ditto with Townie above.

QUOTE]

Townie??? That's new..


Scott will work :thumbup:

 

[MrMogensen]

Cool

Thank you all for speedy help (as usual) !!!

I'll post some pics of the seals soon... I agree it can be a bit confusing to just read!

Just reinserted one of the old thin outer seals and for testing this it seems like the "scraping ability" is from thin edge towards rounded edge. So to keep out dirt (by scraping the returning piston clean) I should insert them as hk_fz6-05 did with thin edge out.

 

[tosh23]

heres another video for ya

[ame=http://www.youtube.com/watch?v=DC_Id6rgP3g]Delboy's Garage, Motorcycle Front Brake Caliper Rebuild Part 2. - YouTube[/ame]

 

[MrMogensen]

Did the job with brake caliper piston seals and all that. And then I had plenty of time to finish up with the nice ABM steel braided brake lines + matching bolts (which has been lying on the shelf for more than half a year) :spank:

First I found it a little weird that the brake line from the Y-splitter on the front fork to right front caliper had an "eye" for bolts in each end instead of an eye in one end (to caliper) and a threaded ending towards the Y-splitter.
Then I found out I was one brake bolt short?
And then... no no and another no... the thread pitch on the brake bolts was wrong. They were 10x1 instead of 10x1,25 :banghead:

Sent an E-mail to the German bike shop where I bought the package and turned out the misunderstanding was that I had ordered the ABM kit for "FZ6 2004-06" and not "FZ6 Fazer". So I guess I got a kit for the previous FZ600 or something. I think it was ABM who made the mixup - but doesn't matter.
Soon it all ends well because the German bike shop (Hein Gericke - Flensbürg) will send me the correct ABM kit for free as long as I send the wrong kit back soon ... all just because I am a good costumer :innocent:

 

[Circle]

Ditto with Townie above.

QUOTE]

Townie??? That's new..


Scott will work :thumbup:

Will do Scott!

Its an Ozzie thing. It all about keeping things efficient (read - lazy)
Jam an 'ie' on the end of things, and bam, you're pretty much speaking most languages in the southern hemisphere.

I get Robbie, Robbo, Robarina, Bob-a-ran. And that just from my kids.

 

[seansi]

I'm about to replace my brake pads and happened to come across this thread. Seems I should probably do the seals as well as the front isn't spinning freely.

Can I get these parts at my local autozone or do I need to order online?
I guess I need to get some more brake fluid as well as this entails bleeding the whole system correct?
I'm also curious if you really need the C clamp when replacing the pads to push the piston down or is there another way?

Thanks in advance

 

[TownsendsFJR1300]

I'm about to replace my brake pads and happened to come across this thread. Seems I should probably do the seals as well as the front isn't spinning freely.

Can I get these parts at my local autozone or do I need to order online?
I guess I need to get some more brake fluid as well as this entails bleeding the whole system correct?
I'm also curious if you really need the C clamp when replacing the pads to push the piston down or is there another way?

Thanks in advance

You need to order them, Auto zone won't have them, if you look up on Babbits, Yamaha is now selling the seals as a kit(you usually had to buy several kits). I would stick with OEM seals.


Here ya go;

2006 Yamaha FZ-6 (FZS6V) Front Brake Caliper | Babbitts Online Part #7 I believe you need two kits, one for each side so call them first


Your S1 only two pistons on each side. Gently push the pads in slightly (I put a thin screw driver in between the rotor and pad, and spread them MAYBE 1/16"). Remove the caliper, then the pads. Then use the brake lever and brake fluid and hydralically push the pistons out with the brake lever. An air compressor comes in VERY handy if the pistons don't wan't to come out. Use air to blow them out. You'll have at one on each side out or most of the way out just hydrallically.

And put away the c-clamp, thats for cages only...