Brake Replacement Question

I'm thinking that your rear pedal felt soft because it was extending the front pistons, after they had been retracted. After the pistons were in contact with the pads, the pedal would have firmed up. I think you'll be fine.

Don't forget that the fluid needs to be flushed every two years.

Ride Safe
John and Janis

Nashcat beat me to it.....that is likely the cause. Just to be safe though, a full bleed is cheap to do, and will provide peace of mind. I do it every year.

If you have no idea when the hydraulic fluid throughout the entire system was serviced I would do a complete flush and bleed. The ST1300 has a system prone to rear brake problems if the basic services are not done. It's not hard to do and you will be safer and more confident to ride the bike where ever you want to go. The service is on a 12,000 or two year interval and must be done in the proper sequence of bleed valves.

There are lots of resources here to help.

I did quite a bit of riding in the mountains this past weekend and noticed that there was high-pitched whine just briefly each time I first started to apply pressure to the rear brake. The brakes seem to be working fine, but over a couple of days that initial whine for just a fraction of a second made me wonder if that's my signal that the rear pads are worn out? I would estimate 4k to 6k miles since the rear pads were replaced and wondered if anyone else has encountered this or has some advice as to what that annoying sound is caused by? Once full pressure was applied or if I was coming to a full stop that loud whine disappeared.

Thad1971 said:

I did quite a bit of riding in the mountains this past weekend and noticed that there was high-pitched whine just briefly each time I first started to apply pressure to the rear brake. The brakes seem to be working fine, but over a couple of days that initial whine for just a fraction of a second made me wonder if that's my signal that the rear pads are worn out? I would estimate 4k to 6k miles since the rear pads were replaced and wondered if anyone else has encountered this or has some advice as to what that annoying sound is caused by? Once full pressure was applied or if I was coming to a full stop that loud whine disappeared.

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That's pretty low mileage to have worn brakes, if that is the case then maybe your SMC is sticking or you need a brake bleed. All your pads have a wear indicator. A notch that if you get to it, you should replace the pads. I think your initial noise was maybe just the new pads adjusting to the surface of the rotor, sometimes they make some noise, sometimes not.. When I used to use ebc pads they would always make noise to me so I only go with OEM pads.

Thanks for the info. Turned out to be some grit and grime was making the rear brakes emit a high-pitched squeal. I had replaced the front pads, but on further inspection the rear pads were down to about 20 percent and have now been replaced as well. Rear tire had some weird cupping and replaced it at 5k miles (normally the pr-4 gets up to about 9k for me), but I have been reading up on the suspension issues on an ST1300 as my bike has just over 53k miles and I am starting to feel every bump in the road. Planning to go out and test ride again today with the saddlebags attached and some weight on the rear seat, but I suspect it may be time to upgrade the suspension.