Replacing rear brake pads - back wheel virtually locked

Changing the rear brake pads should be easy eh?

Changing the pads on my wife's F800R
The R clip and retaining pin come out fine, the piston retracts fine, and I can compress the caliper so that I can fit in the brake pad behind the disc, but it is so tight when you release the compression of the caliper, that the back wheel is virtually locked.
The other pad at the front of the disc has plenty of space

The pads are identically shaped, with the only difference being the thickness of the new ones, as there's no wear. I've fitted both new pads and got pedal pressure back, but the "rear" of the two pads is still so tight, and locking the wheel even with the caliper still pushed in

When I put the old thinner pads back in everything works fine.

Am I missing some sort of adjustment which would centralise the brake disc in the gap between the two pads?
Thanks in advance

I am not an expert at all - but struggled last week to free the sliding pin on my rear brake - the Pins that allow the caliper to slide to accommodate the pad thickness changes.

this post helped me - i know it is a 12GSA but it may be the same for your F800R

https://advrider.com/f/threads/2009-r1200gs-se-seized-rear-caliper.816543/

weealwyn said:

I am not an expert at all - but struggled last week to free the sliding pin on my rear brake - the Pins that allow the caliper to slide to accommodate the pad thickness changes.

this post helped me - i know it is a 12GSA but it may be the same for your F800R

https://advrider.com/f/threads/2009-r1200gs-se-seized-rear-caliper.816543/

Click to expand...

Pretty sure it's this after eliminating everything else. Thanks for advice.

Always take a little bit of sandpaper and give the pin a smoothing and then a tiny swipe of copper grease.

The caliper should slide back and stay back.

If it feels spongy and as though there is some compression behind it, then there may either be a build up of grease or air in the sliding pin cavity, that is not getting vented out through the circular bellows.

As the other posts have said could also be a seized pin, but then you wouldn't be able to slide it very easily in the first place.

Take it apart, pull the caliper off of the pin, clean, regrease and assemble.

Just watch how much grease you put on the pin or in the cavity as that will put you back in the same position.

In the past, when this has happed I have used a small screwdriver to lift the edge of the bellows and watched a 'squrim' of grease exude from the gap as the caliper slides back.

Just my thoughts.

Good Luck

Good Job!

mine was completely seized - took me a couple of days to work up the courage needed to hit it really hard with a soft(ish) faced hammer after securing bracket in vice.

Pin ended up being bent as well as seized and needed some 'attitudinal correction' with aforementioned hammer.

since last weekend have covered a load of miles and all seems well thankfully.

now onto the next issue

alwyn