Harley Davidson Forums banner

1 - 12 of 12 Posts

·
Addicted Since 2010
Joined
·
7,845 Posts
Discussion Starter #1
I'm actually asking this one for a friend. He has a roadster 1200 04 almost the same as mine with 15k miles. The rear brake works fine. Brakes hard, locks the tire no problem....but it is way low. By that I mean that it doesn't engage quickly. You push it halfway down and finally the brake starts to kick in. We tried rebleeding it which didn't change it at all. We didn't fully flush and rebleed which we can do, but I'm not sure it will help.
Master cylinder bad maybe?
Its not a warped rotor... At least from the perspective that you can't "pump up" the brakes to get good feel back like you can if a rotor is warped. Never runout tested it though...
Suggestions?

Sent from Motorcycle.com Free App
 

·
Registered
Joined
·
38,921 Posts
How do the pads look? Are they glazed over?
 

·
Registered
Joined
·
3,173 Posts
I'm actually asking this one for a friend. He has a roadster 1200 04 almost the same as mine with 15k miles. The rear brake works fine. Brakes hard, locks the tire no problem....but it is way low. By that I mean that it doesn't engage quickly. You push it halfway down and finally the brake starts to kick in. We tried rebleeding it which didn't change it at all. We didn't fully flush and rebleed which we can do, but I'm not sure it will help.
Master cylinder bad maybe?
Its not a warped rotor... At least from the perspective that you can't "pump up" the brakes to get good feel back like you can if a rotor is warped. Never runout tested it though...
Suggestions?

Sent from Motorcycle.com Free App
Had the same issue you describe on my Dyna. Bled several times, adjusted travel, etc., with no improvement. Bleeding under vacuum and fresh fluid took care of it.

Sent from Motorcycle.com Free App
 

·
Addicted Since 2010
Joined
·
7,845 Posts
Discussion Starter #5
How do the pads look? Are they glazed over?
Hard to say for sure as i haven't had them off, but
From looking at them closely and removing the upper pin they did look OK.




Had the same issue you describe on my Dyna. Bled several times, adjusted travel, etc., with no improvement. Bleeding under vacuum and fresh fluid took care of it.


Sent from Motorcycle.com Free App
I have a vaccum bleeder and we will get new fluid so we can try that. Its worth a shot for sure anyway.

Thanks for the suggestions!!

Sent from Motorcycle.com Free App
 

·
Registered
Joined
·
3,483 Posts
Take the caliber off, clean the outside of the pistons and dust boots. Carefully "lube" the outside of the piston and dust boot junction with DOT 5 fluid. Re-install, bleed carefully. Should cure the problem. Sometimes the pistons will retract too far, because of dirt, etc on the boot and pistons. Sounds like your problem.
 

·
Addicted Since 2010
Joined
·
7,845 Posts
Discussion Starter #7
Take the caliber off, clean the outside of the pistons and dust boots. Carefully "lube" the outside of the piston and dust boot junction with DOT 5 fluid. Re-install, bleed carefully. Should cure the problem. Sometimes the pistons will retract too far, because of dirt, etc on the boot and pistons. Sounds like your problem.
I was going to do this....but didn't feel like taking the tire off just to get the caliper off. Do you have to though? I'm trying to think now what the SM says. I'll have to look.

Anyways....next weekend possibly, some time we are both free we will do all of this stuff and see how it goes. Thanks guys.

Sent from Motorcycle.com Free App
 

·
Registered
Joined
·
60 Posts
I will be surprised if this isn't a rotor issue. Seems to me the problem is being caused by rotor run out pushing the pads back to far so it takes more pedal travel to get them back to the rotor.
 

·
Addicted Since 2010
Joined
·
7,845 Posts
Discussion Starter #9
I will be surprised if this isn't a rotor issue. Seems to me the problem is being caused by rotor run out pushing the pads back to far so it takes more pedal travel to get them back to the rotor.
I would agree, but you can't feel any pulsing. Also when the bike is sitting you can't pump them back onto the rotor to get pedal feel back. If that makes sense.

What say you?

Sent from Motorcycle.com Free App
 

·
Registered
Joined
·
11 Posts
Take the caliber off, clean the outside of the pistons and dust boots. Carefully "lube" the outside of the piston and dust boot junction with DOT 5 fluid. Re-install, bleed carefully. Should cure the problem. Sometimes the pistons will retract too far, because of dirt, etc on the boot and pistons. Sounds like your problem.
You don't have air in the system all the sudden, he give you the simple answer above, it is hard to visualize why, but it will fix your problem for the cost of a can of brake cleaner and a half hour.
 

·
Registered
Joined
·
3,483 Posts
Now, the answer I gave above does depend on the rear wheel being aligned in the bike. If the rear wheel is a little skewed, that could be the problem. I assumed the wheel had not been messed with before the problem appeared.
 

·
Addicted Since 2010
Joined
·
7,845 Posts
Discussion Starter #12
Now, the answer I gave above does depend on the rear wheel being aligned in the bike. If the rear wheel is a little skewed, that could be the problem. I assumed the wheel had not been messed with before the problem appeared.
Nope. Hasn't been messed with.

Sent from Motorcycle.com Free App
 
1 - 12 of 12 Posts
Top