Front Brake Pad Issue

[Johno]

The front brake pads in my K5 were installed on the bike when I purchased it with unknown history. I have covered only 17,000 kms so their total mileage is unknown.
I've checked the brake pads for wear regularly
I usually just remove the caliper cover to check the pads for wear but decided to remove the pads from the caliper on this occasion.

The left caliper brake pads are seen below in the first picture.

The right caliper pads in the second photo.

The right caliper pads appear to be wearing evenly as expected.
The left pad on the left caliper looks as if a foreign object had been lodged between the disc and the pad to cause the damage to the pad, however there is no corresponding marks on the brake disc.

Is this just a case of the left brake pad breaking down and new brake pads will remedy the issue or is there something else gone wrong.

Any thoughts and opinions would be appreciated.

[Kiwifruit]

Seems odd the radius of the damage to the pad is different to the wear from braking.

[grog]

I agree Col. Wear marks consistent. Must be just pad material no good. Very strange.

[Johno]

 When I removed the pads from each of the calipers I sprayed the pistons with brake cleaner to remove some of the pad dust present. None of the seals were leaking and all appeared OK. However the pads on the right hand caliper slid back easily whereas the pads for the left caliper showed more resistance to returning them into position. The pistons on the left caliper were not equally proud of the caliper body as those on the right caliper.

[Kiwifruit]

Wonder if it had lost a caliper bolt, say the caliper moved on one bolt could the pads foul on the bobbins.
Too wet for me to get out to the shed and have a look tonight.

[seth]

Might be worth checking for corrosion behind the seals as that'll make things higher in the calipers .
Hope you get everything sorted .

[Hooli]

That looks just like when I've lost the pad retaining pin and the pads rubbed on the bobbins.

As to the sticky pistons, had you pumped the RH caliper pistons back out before trying to push the LH caliper pistons in? If not and you hadn't taken the lid off the master cylinder you might have just run out of room in the system for the fluid to go.

[Eric GSX1400K3]

I agree with hooli, looks like the worn pad has not been held in place with  the retaining pin and has worn on the bobbins or shoulder of the rotor. Good pick up.

[Johno]

Thanks everyone for your responses.

Hooli you are spot on. I suspected it was caused by a bobbin but I wasn't sure how it could happen.

The pad retaining pin could be the only explanation.

New pads on the way

[Hooli]

It's why I threadlock the retaining pins these days, now my bike is getting old they sometimes come loose with vibration as I ride. It never used to happen.

[VladTepes]

now my bike is getting old

There's no such thing as an old GSX1400 - just one that's been loved for more years.

[Big Phil]

But there are also those that have been both loved and also CARED FOR😂🤣😂

[KiwiCol]

Hooli cares,       just not a lot!