no rear brake but front is fine '04 ST1300, non ABS

[Rick King]

So my rear brake is non-existent. I haven't had the bike too long and it has never worked. Front works great. This is a non-ABS model. I've put bike on center stand and spun rear wheel then applied FRONT brake and it has no effect on rear wheel. What is the problem w/ rear brake? Any ideas? There is fluid in the rear master reservoir but the lever just goes all the way down w/ no braking. I did try bleeding rear once w/ no luck.
I searched and searched and couldn't find this specific problem anywhere.
Thanks in advance to the minds in the know.

 

[Mellow]

So my rear brake is non-existent. I haven't had the bike too long and it has never worked. Front works great. This is a non-ABS model. I've put bike on center stand and spun rear wheel then applied FRONT brake and it has no effect on rear wheel. What is the problem w/ rear brake? Any ideas? There is fluid in the rear master reservoir but the lever just goes all the way down w/ no braking. I did try bleeding rear once w/ no luck.
I searched and searched and couldn't find this specific problem anywhere.
Thanks in advance to the minds in the know.

That's normal... the front brake action has to be on a MOVING bike, the SMC on the left side of the front wheel will move upwards when the front brake grabs and will activate the rear brake.

You can spin the back wheel and push up on the smc which should work.

 

[BakerBoy]

All ST1300 models are linked brakes.

First, you need to know whether it is the rear brake caliper assembly, or if it is the rear brake pedal hydraulic actuator/piston (I suspect the latter). To help diagnose, with the bike on the centerstand, have someone rotate the rear wheel (engine off, transmission in neutral) with you at the SMC/caliper assembly on the front left disc. While the other person is turning the rear wheel by hand, you rotate the SMC forward (pull the SMC towards the left fork tube). If you're able to stop the rear wheel turning while pulling the SMC forward, at least part of the rear brake is working and it suggests proportioning valve is working. If so, it more strongly implies that the rear brake pedal hydraulic actuator/piston isn't working (perhaps due to air bubbles, or failed seals).

[Stopping as there's too much to discuss. Try the above first and report back, please]

Edit: I thought you said the rear pedal does nothing to stop the rear wheel. Ignore this post.

 

[Rick King]

The pedal I'm having trouble with IS the REAR pedal. When I push the rear pedal down it goes all the way down w/ no rear brake effect. I put the bike on centerstand and hit the FRONT brake just to rule out the linked issue but Mellow has shown that I need to move the SMC by hand to check this properly. I'll do that and if the rear wheel stops that will show that at least part of the rear caliper is working.
So your post Bakerboy is heading in the right direction. I'll report back.
The puzzling thing to me is that there is no fluid loss or leak anywhere. I would think a rear actuator/piston failure would cause a leak. And by the way, where is this part exactly? Is it directly connected to the brake pedal?

 

[970mike]

Sounds like you have air in the brake system, you will need to do a complete flush of the brake system.

 

[Anna'sDad]

Perhaps this diagram will assist you in visualizing the linked brake system that Honda uses on the ST1300.