ST1300 Front Brakes do not release

[Igofar]

As far as your front brake issues, are you using OEM pads or aftermarket EBC pads?
While extending the pistons a little for cleaning is never a bad thing, you may need to remove the pistons and clean behind them, as well as under the seals with a wooden toothpick.
I often find sludge behind the pistons on folks bikes.

 

[jfheath]

I can't add anything more to what has been said - except....

Reading through this post again, you have said a few times that the front brake is not releasing.

When you remove the hoses for the SMC, you have the opportunity to check the behaviour of the front brakes without getting any effect from the rear system. This would be when the rear has been emptied and the front system hasn't been touched.

If you take @Igofar 's suggestion and clean up behind the pistons, you have the same opportunity to check them again when you are reassembling - after filling up and bleeding the front system before filling up the rear system. The front brake lines are completely separate and can be filled and bled without any of the rear lines being connected. (the rear line includes the front centre pistons, the SMC inlet and outlet ports and both inlet ports at the rear caliper )

Although the front line can be made fully operational, you should not test the bike on the road in this condition !

Note - if you are doing a full brake service, this should not be necessary. Everything should just work afterwards. But if you want to reassure yourself about the front brakes, the opportunity is there.

 

[XS Michael]

Hello from Germany,

we replaced the complete secondary master Cylinder and the blocking of the back-brake is gone. The SMC was opened by an experienced (retired) specialist and the photos are posted in the german forum. Yes, it was dirty an rusted inside. Not a new information for you. Interesting: Honda changed the SMC (and the number) - the new SMC looked different.
I know, I started the thread asking for the front brake - not for the back brake. The reason is: The blocking of the backbrake was relatively new - it appeared just 2 months ago. The opening of the frontbrake seams to be ok - not as good as it could be but: ok. Said the specialist.
Next weekend we start up to Lofoten-Islands - and I am happy, that the brake is ok now. The PAN is still the best long-distance bike which I know - I am still not old enough for a Goldwing

Greetings and have a good time! Michael

 

[Sadlsor]

Still not old enough for a GoldWing!
That's just precious.
My concern is, once I DO get old enough, that by then it will be too heavy for me!

 

[Igofar]

Hello from Germany,

we replaced the complete secondary master Cylinder and the blocking of the back-brake is gone. The SMC was opened by an experienced (retired) specialist and the photos are posted in the german forum. Yes, it was dirty an rusted inside. Not a new information for you. Interesting: Honda changed the SMC (and the number) - the new SMC looked different.
I know, I started the thread asking for the front brake - not for the back brake. The reason is: The blocking of the backbrake was relatively new - it appeared just 2 months ago. The opening of the frontbrake seams to be ok - not as good as it could be but: ok. Said the specialist.
Next weekend we start up to Lofoten-Islands - and I am happy, that the brake is ok now. The PAN is still the best long-distance bike which I know - I am still not old enough for a Goldwing

Greetings and have a good time! Michael

Glad to hear you got your brake issues sorted out.
Ride safe and enjoy your bike.
Safe travels.