675 Street Triple R 2014 - Weak Front Brakes

Hello,

I´ve bought a 2014 Street Triple R about a month and a half ago with 39 000 km´s from new.
Bike has ABS.
When I got the bike, front brakes were fantastically sharp, only one finger was needed to stop.
I´m now at 40 000 km´s, and front brakes started to feel very weak. You need more power and they aren´t sharp as before. They almost remind me of my old Kawasaki Z750 brakes, which were simply rubbish.

The bike got a new brake fluid about a month ago, before I bought it (got invoice from service).
Brake pads seems like they have a lot of meat remaining.
What would you suggest?
Get off the calipers, clean them with hot soapy water? Try to bleed the brakes? Or is this some common problem?

PS: The rear brake is very weak too (it needs quite a lot of force to start braking when comparing with my old Z750).

Thank you for advice.

 

Sorry, I did not understand your question. What do you mean by that? If is the fluid at the same level?

 

Haven´t checked the stripped calipers yet. What would that mean, if they are glazed?
I have an invoice, that there are installed Brembo Sinter pads (07KA23SA).

 

Thank you.

Do you know, where the leak could be? I read about master cylinder failure (new piston kit should repair it).˝

Or somewhere else? The bike has new fluid from this July.

 

So Today I managed to strip the calipers. Looked pretty dirty, probably never been cleaned. Pads were changed once. I cleaned the calipers and tried to pump levers and look for seized piston. The bigger pistons were moving freely and on every side the one piston from the smaller duo was a bit stuck. I got them moving by pumping and pressing them back in.
I did not have time to test ride the bike sadly, so don’t know, if it helped yet, but as someone mentioned above, the lever feels a bit spongy, so next up is brake fluid change + bleed. I don’t have diagnostics or OBD and TuneECU app, so can’t bleed the abs, but if is the lever spongy, than the air must be between master cylinder and calipers I think. Strange, that the fluid has been changed two months ago.. here are some photos from the action

 

So I´ve ridden the bike and.. well sometimes the brakes feel very nice and sometimes they feel very week.. depends on situation. Very strange.
I took of the front lever to check the master cylinder piston seal, but it looks like its fine. No sign of any leaks.

It is now cold outside, so I will probably continue this mission next year, cuz the bike will be sleeping over winter

Next thing to do is the brake fluid change/bleed.

 

So what you suggest? Tak them off again a clean them one more time?

 

Hello again guys..

I was just thinking again about the situation with weak front brakes.

Is there any chance that air can get from the ABS module to the front brake circuit?

Because when I got the bike, I tried to block rear end wheel, to know, how the ABS behave and I think, that the FRONT brakes got worse after ABS was handling the blocked rear wheel.. But again, I´m not 100% sure.. just asking, if is this possible or not.

 

And if I blocked the rear wheel, is it possible that air would get to the front brakes system?