Rear breaks dragging! what to check first?

So I took my rear wheel/ swing arm off to install my motor and when I replaced my rear break caliper seems to always be slightly engaged. My break light stays on and I can feel resistence while pushing my bike in neutral. I was thinking maybe I didnt route the break line correctly but am not sure. Is there any easy adjusent for

This I should check before I get too deep into it?

If your rear brake light stays on, it's not the cable, unless you installed an after market banjo bolt type hydraulic switch. The break light switch is actuated by a bolt on a tab on the bottom of the brake lever. if that bolt is screwed out too much, it will create both your symptoms.

Edited by Nellisvan

Thanks man, I did see that but never thought if adjusting it because it seemed fine before. I will guve that bolt a few turns and see if it solves my problem

Well that didnt work. It seems The brake light and stuck breaks are 2 different problems. The brake light switch does not seem to be functioning as it should. Engaged or not the brake light stays on? As for the brakes, the caliper only disengages maybe 20% of what it should after the brakes are applied. I guess next step is to bleed the rear caliper? If that does not work am I looking at a busted caliper?

Check for free movement of all linkage to the master cylinder. I'm heading into the garage right now with the same issue. It doesn't sound like a bleed-related issue to me

Haha Ill be headed straight to the garage after work. I dont think its a bleed issue either but I have never changed fluid/bled since I purchased the bike used so I figure its not a bad idea. How would I rule out a bad master cylinder?

Again, the fact that the brake light stays on indicates that it's actually the pedal that is pushing down for some reason. I guess it's possible the if the piston in the master cylinder, or one of the seals are damaged, it could prevent complete extension to release system pressure. Have you tried to lift the brake pedal up to see if the light goes off and the master cylinder piston extends out more than on it's own return?

Or it could be your front brake causing the problems......?

crawl under and look at the bolt. when it disconnects from the switch, the switch makes the circuit = brake light on. 


if it's touching the switch, the light will stay on. 


make sure the adjustment rod is not damaged on the rear brake lever, or the bolt backed out. if the bolt backs out it can put the lever in a bind and keep the brakes partially applied. 


do not ride in this condition. it will over heat, lock, or possibly set fire to the rear hub's grease. seen it happen. it sucks. 

Up until a few days ago if I lifted up on the lever the brake light would go off but now it is stuck on even when the bolt is completely off the switch. I tried messing with the bolt and saw no change in the light or caliper retracting no matter how I adjusted it. The liknage to the master all look fine as far as I can tell. Something else I noticed is that my fluid resivour is completely full to the top. Could this not be allowing fluid back out of the system? I find it hard to believe that this is 2 seperate problems But like I said brake light stays lit weather the switch is engaged or not.

Or it could be your front brake causing the problems......?

I am 95% sure it is the rear as up until a few days ago lifting up on the rear lever turned the brake light off

Well, mine has returned to normal condition after I removed the pedal and cleaned/lubed the whole thing carefully.


Must have been some unseen grit hanging up the pedal. Why not start there and see what happens....either way it's an easy task that gets forgotten too often.

Just because the brake light is ON doesn't mean the brakes are dragging.  You have a spring (part #10) installed between the pedal and frame, right?  There is a long bolt threaded into the brake pedal (underside, part #11) that extends forward and engages a metal tipped switch on the side frame rail.  Loosen the locking nut and thread the bolt into the pedal (for now all the way in), decreasing how much it sticks out towards the front of the bike.


Now check the brakes (regardless of the brake light), are they dragging?  Try pulling up on the brake pedal (by hand), any difference?  With the rear wheel off the ground, transmission in neutral, I can easily rotate the rear wheel by hand.

Parts Diagram:

Have the caliper slide pins been checked? If there rusted it could lock the caliper in place or not let it float. One of mine was rusted.

Worth a look. Good luck

One thing that seldom gets the attention it deserves is the brake pedal bolt/shaft. It should always be kept well greased, that's why there's a groove there, some bikes even have it oring protected against the dirt is is subject to, being down where it is. I know of a bike catching fire during a long transcontinental trip because the pedal got stuck, and the rider only realized what was happening after it was too late, and he was stuck in the middle of the Atacama desert.

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