Rear Brake Grinding

Hi guys, would like to call on some of your VFR wisdom. I have a 2007 VFR800, 14,000 miles on the odometer. Recently, I have been hearing some grinding out of the rear brake. When I put the bike up on the center stand and spin the rear wheel, the scraping/grinding is very apparent and not just some rubbing like I've noticed in the past. I looked at the rear pads, could only see the outside pad without removing the rear wheel, and it looks pretty good. Maybe 4-6mm of pad thickness. I'm seeing some light grooves on the right side of the rotor, the other side is smoother. Not sure if the light grooves in the rotor is normal, haven't checked it in a while.

My next step is to remove the rear wheel, remove the rear caliper, and check the pads and pistons. Fluid has not been changed, it's not clear but not that dark either, was thinking of changing the fluid soon but understand it's a lengthy process.

Should I be able to easily push back all three caliper pistons? How much pad material is enough? Seems like 14k miles is a little soon to be changing rear pads. I don't drive the bike hard, just back and fourth to work, 1/2 city, 1/2 highway commute.

 

Hard to say just what is causing it. Could easily be the inner pad worn to metal even though the outer pad has material on it.
When you take it apart make sure to check clean and regrease (high temp moly grease or special slide grease) the caliper slides. A sticking slide can cause uneven pad wear both from pad to pad and across the pads , depending on which slide(s) are sticking and how bad.

Just my 2¢ :tranquillity:

May be special steps to changing fluid on your bike, but in general it is as simple as using a large syringe or turkey baster (Don't let the wife catch you) to draw all the old fluid out of the MC resivoir. Then refilling it with fresh fluid, make sure to use the same fluid (Usually Dot4 or maybe Dot5) as the two don't mix.
Once you refilled the MC with fresh fluid then you will need to bleed the brake ,keeping an eye on the fluid level in the MC, until clear fluid comes out.

That's pretty much it , it may not hurt to wipe any residue out of the Master Cylinder with a lint free cloth. Keep in mind brake fluid will ruin paint and most any other surface if it is left on it. So wipe any leaked or spilled fluid off ASAP

 

Thanks DeeBee, I posted first to see if my issue happens to be common on the 6th gen VFR's. Doesn't seem so if others haven't jumped in to let me know they've seen this before.

I hope to get time today to remove the wheel and pull the caliper. I will need to get some brake cleaner and moly grease from the local auto parts store before I start. I am familiar with changing brake/clutch fluids in my cars, just never did it on the VFR. I guess there is an particular order/sequence for bleeding the linked braking system?

I will update you on what I find when I dismount the rear caliper.

 

I'd just start by changing the pads. Inside one is probably worn down to the backing plate and tearing up your rotor. You don't have to change the fluid or bleed anything. Just open the rear reservoir when driving the pistons back into the caliper so that it can safely overflow.

 

Removed the rear caliper after work this evening. Nothing to worry about, the inside pad was worn down and making the noise. I will pick up a set of OEM pads tomorrow. In the meantime I cleaned the pistons, pushed them back, cleaned the caliper and will grease the sliding pins with the proper grease. Thanks for your help guys!