1150 front brake piston hole

[hughguzzi]

Hi all - just cleaning up my front brake callipers (pads good) before a trip.
Ive discovered one piston has a hole in its surface that contacts the back of the pad.
Most pistons I have seen are a hollow cup so the 'lip' of the cup contacts the pad.
There is no fluid leak and everything moves and works fine !
Is this a cap 'wear insert' in the piston or should the piston be replaced (or all 4 ?)

anyone help with this ?
cheers

 

[Timolgra]

Don't worry about it, it's just a cover and someone's probably pushed the piston back incorrectly breaking it.

 

[hughguzzi]

Ok but the 'cover' seems to be a softer material and sits slightly proud of the piston rim - so it touches the back of the pad when the piston rim does not.
What is the purpose of this 'insert' into the piston cup creating a pad contact face ?
If it broke up would it potentially jam the brake on ?

 

[Roadcaptain]

hugh I think half of mine have holes in and never caused a problem (famous last words)

 

[DrFarkoff]

Its an anti squeal cushion (one piston shape of plastic inside the main piston but "open end" to "open end" if that makes sense) made of a brittle plastic If you push too hard to lever pistons back you can crack or hole them

As long as the circumference of the inner cup is unbroken they will be fine

 

[hughguzzi]

Ok thanks chaps - its a small hole about 0.5 cm pretty much in the centre - if its nought to worry about I will leave them, as there are no leaks and pistons are working lovely.
Recently had SS hoses fitted and fresh fluids.
Stripping the callipers down to replace pistons and seals just before a europe trip might cause me more problems !!

Been doing quite a lot recently -
clean up and paint engine casings,
clean up exhausts (and fix broken stud)
replace rear gearbox output seal, gaiter and gear change seal
grease up swing arm bearings
new final drive pivot bearings
re-align shaft drive and grease splines
fit Stebel horn
Full service oils and filters
etc etc !

At 62000 miles I suppose I should expect a few bits but I 'loves' my 1150 !

Cheers

 

[King Rat]

Ok thanks chaps - its a small hole about 0.5 cm pretty much in the centre - if its nought to worry about I will leave them, as there are no leaks and pistons are working lovely.
Recently had SS hoses fitted and fresh fluids.
Stripping the callipers down to replace pistons and seals just before a europe trip might cause me more problems !!

Been doing quite a lot recently -
clean up and paint engine casings,
clean up exhausts (and fix broken stud)
replace rear gearbox output seal, gaiter and gear change seal
grease up swing arm bearings
new final drive pivot bearings
re-align shaft drive and grease splines
fit Stebel horn
Full service oils and filters
etc etc !

At 62000 miles I suppose I should expect a few bits but I 'loves' my 1150 !

Cheers

That's only just run-in

This was 600 miles ago, on my way to The faroe Islands....I am still here. Report to follow.

 

[hughguzzi]

Hey well done bud !!
thats impressive mileage - any major issues along the way, or have you got a particularily good un !?

Had my clutch done last summer thats the biggest thing so far for me !

 

[kennyc]

Ok thanks chaps - its a small hole about 0.5 cm pretty much in the centre - if its nought to worry about I will leave them, as there are no leaks and pistons are working lovely.
Recently had SS hoses fitted and fresh fluids.
Stripping the callipers down to replace pistons and seals just before a europe trip might cause me more problems !!

Been doing quite a lot recently -
clean up and paint engine casings,
clean up exhausts (and fix broken stud)
replace rear gearbox output seal, gaiter and gear change seal
grease up swing arm bearings
new final drive pivot bearings
re-align shaft drive and grease splines
fit Stebel horn
Full service oils and filters
etc etc !

At 62000 miles I suppose I should expect a few bits but I 'loves' my 1150 !

Cheers

Don't forget to take a spare final drive large bearing and seal (I did and that didn't work out too well )

 

[King Rat]

Still on the original clutch, discs, suspension, final drive bearing did break up at around 65,000, but it was done under warranty, so I don't care. The coil stick things are one of the problem areas - I have used UV cure nail varnish stuff to paint my new ones with, to try and "stop the rot" - they are made of acid impregnated tin foil thich steel, given a lick and promise of some paint.....even ACF50 on them regularly didn't help much. There has to be a way of protecting them so they don'r corrode in 6 months.

 

[Fanum]

Still on the original clutch, discs, suspension, final drive bearing did break up at around 65,000, but it was done under warranty, so I don't care. The coil stick things are one of the problem areas - I have used UV cure nail varnish stuff to paint my new ones with, to try and "stop the rot" - they are made of acid impregnated tin foil thich steel, given a lick and promise of some paint.....even ACF50 on them regularly didn't help much. There has to be a way of protecting them so they don'r corrode in 6 months.

Yep......re-position the coil sticks under the tank and run conventional HT leads from them to the plugs.......simple

 

[King Rat]

Yep......re-position the coil sticks under the tank and run conventional HT leads from them to the plugs.......simple

MARVELLOUS IDEA - how do you protect the casings when in-situ under the tank please?

 

[hughguzzi]

I assume it's only the twin spark that has the 'stick coils' (at £85each) mine is single spark and the caps look long but normal and I'm pretty sure the coils are up under the tank !?