Front Caliper pistons seized, wish I hadn't looked

[Black Rooster]

i have never done that, or needed to

...and how flat was the oil stone?

the oil stone was my m8s in his workshop and it was very flat was only to take the alloy corrison off the faces

and it was only 2 or three wipes over it

and it was okay after we finished it no leaks so job was a good yun and it was about 15 years ago so thinks are a bit fuzzy lol

 

[swissrob]

Use 3000 grit cloth and a sheet of glass if need be

Sent from my GT-I9300 using Tapatalk 2

 

[richierex]

the oil stone was my m8s in his workshop and it was very flat was only to take the alloy corrison off the faces

and it was only 2 or three wipes over it

and it was okay after we finished it no leaks so job was a good yun and it was about 15 years ago so thinks are a bit fuzzy lol

Well as its the o rings that seal, who cares about the surface being flat, as long as its clean. spend the time polishing the BMW letters or BREMBO on the front.

 

[ozziesda]

Success!

Well lads and lassies

The little 'square rings' eventually arrived from Cradley Kawasaki this morning, I have the rebuilt calipers back on the bike and all bled with no leaks whatsoever.

Admittedly, there is a tiny bit of spongy-ness in the lever which I recon is from a small trapped air bubble but that should rise up to the reservoir overnight. Even with the tiny bit of spongy-ness, the brakes are extremely powerful so I'm going for a spin tomorrow to get a bit of heat into the brakes. That will definitely shift the bubble if its not gone by itself in the morning.

I'm going to do an oil and filter change, gearbox oil change and final drive oil change too when I get back tomorrow so she's in tip top shape for the next 6k miles.

Dave

 

[ozziesda]

90 mile spin today - brakes 100% fine. Air bubble released itself when the calipers warmed up a little and the spongyness disappeared. Lovely progressive braking now.

I was so happy with my BMW cherry popping proper spin on the GSA, when I got home she was treated to a gearbox oil change and an engine oil and filter change!!

Moral of the story - You can split BMW/Tokico calipers providing you have the correct centre seals to rebuild them.

Torque value for the joining bolts we used was 25nm or 18 ft-lbs. 'Felt' about right during the re-assembly too. We got this from a Kawasaki caliper rebuild thread for calipers that looked very similar.

Now its time to celebrate.



Oh and here's a few pics from earlier

 

[Mzokk]

All Bike brakes have crap corrosion protection.. Try this.http://www.ukgser.com/forums/showthread.php?t=38909

 

[Slipperyeel]

This topic has been interesting. One detail though (back to the sealing washers for the calipers). The square section O-rings specified earlier, do they fit the Brembo calipers?

Thanks if anyone can clarify this point.

 

[Bendy toy]

All Bike brakes have crap corrosion protection..{/url]

One of my pet hates.

Why dont bikes have brass liners in the calipers (stainless can react with aluminium)? then we wouldn't need to replace the seals. Of course,that's the reason... Oh silly me.

 

[bobsnew]

With a bit of digging around I found that these are available individually from Kawasaki (part no. 43049- 1004) and Honda (part no. 45103-MEL-003) and are about £2.25 each.
I am still waiting for a delivery from Cradley Kawasaki of these seals.


The update is, as advised by I live a short distance from Cradley Kawasak[, I had the part number as shown above, I was very impressed with the level of knowledge of the parts chappie, quoted the number & he immediately recognised the seals, in stock. Sold separately, no crap as given by BMW main stealer, oh you have to buy new calipers, sir just, £267 plus vat each side.

total cost of seals £10.85. Job done. Yes its a pain getting the Torx bolts out, but sweat & perseverance its do-able. Thanks for the advice chaps all that remains is to make the Brake bleeding tool as shown on another site.