Rear caliper dust seals from Wemoto are too wide

[redmandan]

Hi guys

My latest bit of maintenance has led me to overhaul the rear caliper. I've had nothing but success with Wemoto before so ordered some new seals and pads from there. After finally getting both pistons moving with compressed air, then pulling the old seals out of one side, the new brake fluid seal went in no problems but the dust seal just would not seat in the groove properly. It was almost like it was 20% too big in circumference although it was a perfect fit around the piston alone.

Eventually I held it up against the old dust seal and it is indeed noticeably thicker.

https://imgur.com/a/WOQBVKA

With this extra thickness it won't seat in the groove of the caliper and is effectively useless. I didn't realise Wemoto weren't OEM but I thought they would be better than this. The brake fluid seal seems to be the same size and circumference as the old one but how can I be sure it won't leak brake fluid all over the place when I need to stop.

I will ping an email off to Wemoto and see what they say.

Where do you all get your seals from?

[Trebus]

I’ve had the same with some aftermarket seals on one occasion with a different bike. Fowlers will do the OEM seals but they’ll be more expensive inevitably.

[His Dudeness]

In my experience after market seals are a bit hit and miss so I always get seals from Yamaha using the part numbers in the parts catalogue. The parts catalogue is in the download section http://foc-u.co.uk/index.php?action=downloads;cat=2  You know for sure the seals are the correct size and material when you get them from Yamaha.

[His Dudeness]

You can get Yamaha seals from wemoto if you change the search bar from "pattern parts" to "OEM part number". https://www.wemoto.com/parts Then put in the part number from the part number catalogue

When you're fitting the new seals make sure you scrape out the groove where the seal goes really well using a pick. It doesn't take much crude to push the seal out.

[redmandan]

Thanks guys. only 6 quid for both pistons from Wemoto. OEM ones from Fowlers are 28  :'(


That's the price of peace of mind though. Hopefully I'll get my cash back from Wemoto.


Maybe I won't overhaul the front calipers just yet then, I'll have to eat rice for a month or so first. Looks to be about 160 for seals for both calipers.

[74eldiablo]

So this is interesting from me as i have just completely stripped my rear caliper (pics on streetfazer thread in a bit)
as the original yamaha seals are about £26 for a set i opted for some cheaper alternatives as well, now i can fully appreciate that original is best but £6.50 each rubber seal is foccin ludicrous, i hope the ones i ordered are within tolereance otherwise i guess it will be a case of £26 + £8 and a very smitten case of "i told you so"
seems the fzs 600 caliper is utter shite back from 1980's hence why people upgrade, brakes are usually good or bad on any bike but on the fazer the R1 stoppers at the front are tip top whilst the rears are well just parts bin specials as yamaha didnt see fit to have good rear brakes on a sports tourer

[redmandan]

seems the fzs 600 caliper is utter shite back from 1980's hence why people upgrade, brakes are usually good or bad on any bike but on the fazer the R1 stoppers at the front are tip top whilst the rears are well just parts bin specials as yamaha didnt see fit to have good rear brakes on a sports tourer

The blue dot FZS1000 upgrade is looking more and more attractive right now.

[His Dudeness]

I think the stopping power of the rear is fine. The problem with it is that it doesn't clear brake dust very well and it's mounted under the disk so that causes more brake dust build up and that ruins the dust seal. You have to clean them at least once a year to keep them working properly

[74eldiablo]

agree with you 100% dudeness underslung calipers are barry whiteand thanks for your help you know your shit

[74eldiablo]

quote The blue dot FZS1000 upgrade is looking more and more attractive right now.

i think i would like to no doubt, but prices and availability dictate why i should try rebuild this on... easy come easy go it pisses me off that front R1 blue spots are cheaper that blue spot rears.
fuck it i'll buy some brembo monobloks all round  :lol

[redmandan]

If you clean them once a year does that also mean new seals every year or can you also clean the seals up and re-use them?

[His Dudeness]

No problem I only really know about things where I've had the same problem in the past and crappy after market seals are one of them :lol . No, if you clean them regularly you can usually get away with just pumping them out a bit and give them a scrub. You can pump them all the way out and reuse the seals as long as they're in good condition but normally you don't need to pump them all the way out

[Trebus]

Normally you can reuse them unless they balloon up when you take them out. Bit of red rubber grease when sticking it back keeps corrosion build up to a minimum.

[Trebus]

And I recommend getting some piston pliers to give them a turn. This helps to free up any slightly sticky piston without the need to pop them.

[74eldiablo]

personally.. i dont think so you need to change the seals every year, mines done 31k and are original brakes in a 18 year old state, think basically after a rebuild a quick inspection, splash of brake cleaner, a slip of red rubber grease and every 3 year new fluid you good to go.
In all fairness you wouldn't change your car brake seals every year unless the MOT said they were chuffed, brake cleaner, new pads, new discs (if needed) smidge of copperslip and bon voyage
I certainly wont be touching mine for at least a year, full strip down replace clean up parts, new brake pads hoses and seals .. i expect at least a year without a severe deep clean

[74eldiablo]

i'll need your help your dudeness on my streetfazer thread regarding this matter soon, calipers stripped just waiting for a parcel from blighty

[His Dudeness]

Ask away. There's plenty of way more knowledgeable people on here than me. Like I said I only really know about things where I've had the same problem. There's lots of helpful people on here that's one of the good things about this forum.

[unfazed]

I agree with what is being said, pattern seals can be hit and miss especially on the calipers. I too always buy OEM caliper seals.With regards the FZS600 and FZS1000 rear calipers, the main reason the 600 one is troublesome is that the pads are inserted from the top and it only has 2 small drain holes which are easily blocked and the caliper fills with water and in winter it means saltwater., thus in sets the inevitable corrosion. The 1000 on the other is less prone to problems because the Pads are inserted from the bottom which means the water has plenty of room to drain away.
Both rear calipers have the same diameter pistons and both bikes use the same master cylinder.
There is no need to change seals yearly, just regularly non dismantling cleaning of the caliper to prevent the building up of corrosion is all that is required