Front Brakes

My front brakes recently developed a rubbing noise. The sound is similar to when you first apply the brakes lightly and you get that noise that sounds like holes in the rotor rubbing against the pads. Like a ZZZZZ as the rotor spins through the pads.

It's very slight and doesn't seem to drag on the front wheel and the bike freewheels like normal. If I apply the brakes while cruising along the noise gets louder for a while and slowly goes back to a very slight rubbing noise but never goes completely away. It's almost like the pistons in the calipers aren't backing off enough after braking.

I took both calipers off the rotors and the pistons slide in and out with little effort. They weren't dirty but I cleaned them anyway and tried again with the results being the same. So now my thinking is the master cylinder isn't creating enough vacuum to pull the pistons back enough. I also noticed that when I apply the front brake with a strong grip and keep squeezing, I can slowly bring the lever all the way to the throttle handle even though it is resisting very strongly. I tried the same thing on my Road Star and no matter how hard I squeeze, I can only get the lever to go so far.

Does this make sense to anyone?

It's almost like the pistons in the calipers aren't backing off enough after braking.

I also noticed that when I apply the front brake with a strong grip and keep squeezing, I can slowly bring the lever all the way to the throttle handle even though it is resisting very strongly.

Sounds like the master cylinder is leaking by. Rebuild or replace

My front brakes recently developed a rubbing noise. The sound is similar to when you first apply the brakes lightly and you get that noise that sounds like holes in the rotor rubbing against the pads. Like a ZZZZZ as the rotor spins through the pads.

It's very slight and doesn't seem to drag on the front wheel and the bike freewheels like normal. If I apply the brakes while cruising along the noise gets louder for a while and slowly goes back to a very slight rubbing noise but never goes completely away. It's almost like the pistons in the calipers aren't backing off enough after braking.

 

 

I took both calipers off the rotors and the pistons slide in and out with little effort. They weren't dirty but I cleaned them anyway and tried again with the results being the same. So now my thinking is the master cylinder isn't creating enough vacuum to pull the pistons back enough. I also noticed that when I apply the front brake with a strong grip and keep squeezing, I can slowly bring the lever all the way to the throttle handle even though it is resisting very strongly. I tried the same thing on my Road Star and no matter how hard I squeeze, I can only get the lever to go so far.

 

Does this make sense to anyone?

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Steamer is right, you need to service the internals, a caliper and master rebuild are both indicated here. The only way that you can bottom out the lever like that is if the master is bypassing internally, meaning that it is on borrowed time.

Try a new set of pads....

Sounds like the master cylinder is leaking by. Rebuild or replace

 

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Going with what you say. Just ordered a MC rebuild kit.

I did a test run today that convinced me it's the master cylinder. A little unorthodox but Did it anyways. Pulled one of the left caliper off the rotor and placed a piece of metal that same thickness as the rotor in between the pads. Taped it in place and wired secure the caliper to the front fork and took the bike down the street with only the right caliper working. And the results and noise was still there. Got back to my shop and swapped the setup so that the right caliper was off the rotor and the l3eft was on the rotor and got the same results.

Just to be informed: when releasing the brake handle the MC does not bring the pads back, all you are doing is releasing the pressure on the pads so that they no longer bind on the rotor. They will continue to contact the rotor to keep the rotor clean and dry.

Now the continued compression of the MC is an issue, and has been answered already, and it's good to see that you are taking action in that dept.

When I changed pads on the back of my RSV and went with a different compound it had a zzz kind of sound. Come to think of it the XCT does the same thing. Nothing dragging, systems were bled and all good, just makes the goofy sound sometimes

When I changed pads on the back of my RSV and went with a different compound it had a zzz kind of sound. Come to think of it the XCT does the same thing. Nothing dragging, systems were bled and all good, just makes the goofy sound sometimes

HH pads?

HH pads?

I went with HH pads on the front of my Gen 2 and I feel it stops shorter.

VentureFar...

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I went with HH pads on the front of my Gen 2 and I feel it stops shorter.

VentureFar...

 

 

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I have the same problem being able to get the handle to the grip. If I pump it seems to hold better. Where are rebuild kits available?

Just to be informed: when releasing the brake handle the MC does not bring the pads back, all you are doing is releasing the pressure on the pads so that they no longer bind on the rotor. They will continue to contact the rotor to keep the rotor clean and dry.

Now the continued compression of the MC is an issue, and has been answered already, and it's good to see that you are taking action in that dept.

I wondered who was gonna say that. That is exactly right. What you described, your master cylinder needs rebuilt. Be sure to clean out the little holes in the master cylinder. Had mine all but lock up at 70mph one day, did lock up when I got to 20mph. The relief hole stopped up, put pressure on the calipers, the more they overheated, the harder they gripped.

I have the same problem being able to get the handle to the grip. If I pump it seems to hold better. Where are rebuild kits available?

Bought mine off ebay. Also get the Babbitt’s app. Get anything you want there.

Installed the new master cylinder rebuild kit. The good news. I can no longer get the brake handle to touch the handlebar. The bad news, the problem of the brake rub noise was still there. Bought some used calipers off ebay and the noise is gone. Doesn't make sense to me but that's OK as the brakes are back to normal.