Front brake doesn’t feel right since changing front tire

Wheelin

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Hi All -

I was changing out my front tire and followed the procedure of removing the right brake caliper in order to remove the tire. Everything went OK (or so I thought) until after I reinstalled the tire. I made sure that the rotor on the left side of the wheel went in between the brake pads and then reinstalled the right caliper, also making sure that the right side rotor also went in between the brake pads on the right side. I rode the bike around the parking lot and tried to engage the front brake, and nothing happened for a few seconds when engaging the front brakes all the way. After trying a second time, the front brakes activated. I figure that I had jettisoned whatever air might’ve potentially got in the brake hose, but the front brake hasn’t quite felt right since then. I’ve checked and rechecked, and the brake pads are where they’re supposed to be.

Any thoughts on what else I could do?

Thanks,
Wheelin
 

Nikolajsen

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Sorry, no really good idea..
Nothing should happen, when you just remove/reinstall front whell.
Execpt what you felt first time you brake, because the brake have to get close to brake disc first.
Could it be, that you got some "soap" from the tire change, on the brake disc?
 

Wheelin

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Sorry, no really good idea..
Nothing should happen, when you just remove/reinstall front whell.
Execpt what you felt first time you brake, because the brake have to get close to brake disc first.
Could it be, that you got some "soap" from the tire change, on the brake disc?
I guess that’s a possibility.

I’m thinking that I shouldn’t have just left the caliper hanging there as 1) it’s probably not good for the hose and 2) perhaps it allows air to somehow get in there.

I intend to bleed the brakes today, so maybe that’ll solve whatever problems my remain. Could be all in my head for all I know.
 

RCinNC

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What does "not quite right" mean? Can you describe the feeling?

It's not unusual to have that "no brakes" feeling when you first change the brake pads. You have to push the pistons back into the calipers to get the new pads to fit around the rotor, so the first time you apply the brakes, the pistons aren't pushing against anything until the brake pads close the gap between the pad and rotor. You can't jettison air from a brake system in the manner you describe; it's a closed system. Air can't get out (or in) unless you open the system up, which you don't do when you're just changing a brake pad. Leaving the caliper hanging by the hose won't introduce air into the system either, though I wouldn't make a habit of it.

There is a spring that goes back into the caliper after you install the pads. It's that copper colored piece of metal with various bends in it. Did you check and make sure that the spring was reinstalled in the right way?
 

EricV

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I have been just letting the calipers hang during wheel/tire changes for a long time. I'm careful not to knock them around, but I don't think the weight is enough to really be an issue by itself. No, it's not recommended procedure, but I do wire up heavy vehicle calipers. Just don't feel the lighter moto ones require it. That by itself won't let air into the system.

The first part you felt w/o brakes is just from the pistons being pressed out a little during your work. Completely normal.

I do typically remove both calipers when pulling a wheel. It's just not that hard to do.

I think I would want to visually inspect all the pads before I worried about anything else.
 

Wheelin

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What does "not quite right" mean? Can you describe the feeling?
When I engage the front brake, it almost feels like the brake pads are running rough on the rotor—which I intend to inspect.

It's not unusual to have that "no brakes" feeling when you first change the brake pads. You have to push the pistons back into the calipers to get the new pads to fit around the rotor, so the first time you apply the brakes, the pistons aren't pushing against anything until the brake pads close the gap between the pad and rotor. You can't jettison air from a brake system in the manner you describe; it's a closed system. Air can't get out (or in) unless you open the system up, which you don't do when you're just changing a brake pad. Leaving the caliper hanging by the hose won't introduce air into the system either, though I wouldn't make a habit of it.
Newbies like me always appreciate the education. Thanks.

There is a spring that goes back into the caliper after you install the pads. It's that copper colored piece of metal with various bends in it. Did you check and make sure that the spring was reinstalled in the right way?
Yes, I’ve taken that spring out when I’ve inspected the pads. I didn’t (or at least I hope I didn’t) fiddle with it when I removed the caliper to uninstall the front wheel, but I’ll check for that, thanks.
 

Squibb

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If the discs are scored, it could well be that the pads need to bed back in again for normal 'feel' to return - always assuming the discs are otherwise free of corrosion & able to float correctly in their mountings.

However, if there is any sign of air in the system, maybe a need to pump the lever to bring it to the normal biting position, then you will need to bleed the brakes after checking the lines for damage.

BTW, is your ABS still working correctly?
 

WJBertrand

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That first “no brakes” thing is normal. In the process of removing and replacing the wheel, it’s common to have inadvertently pushed the caliper pistons in a little. One should always pump the brake lever (or pedal) a few times any time you’ve messed with the wheel or brakes.

Is it possible you bent one of the rotors slightly? That might give a rough, or even pulsating feeling.


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Wheelin

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BTW, is your ABS still working correctly?
I probably haven't braked hard enough to find that out. At least, I haven't felt the pulsations yet. I should probably do that before I risk my life splitting lanes in lovely SoCal. :eek:
 

Wheelin

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Is it possible you bent one of the rotors slightly? That might give a rough, or even pulsating feeling.


Sent from my iPhone using Tapatalk Pro
Thanks for bringing this up. Sounds like one more thing I need to check, which by my searches on Google indicate that I need to remove the wheel, put it on a tire stand, get some sort of dial indicator to drag lightly on the rotor, and see how much that needle moves around.

Sometimes this DIY stuff really drives me nuts. Yet one more tool to buy...:rolleyes:
 

Wheelin

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Before you tighten the axle and pinch bolts, jounce the front suspension several times with the brakes to ensure everything is in alignment. Might help, my $0.02.
I remember doing that when I changed the front tire a couple of weeks ago. But at my level of mechanical wealth, I'll take any $0.02 that I can get! ;)
 

Wheelin

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Loosen the pinch bolts on the right fork leg, pump the brakes a few times and then tighten the pinch bolts back up and report back.
Will do. I might have to wait until Labor Day morning, as it's getting hotter than Satan's taint out in my garage.

What I really wish is that I could get one of you guys to ride my bike and give me your impressions. This could all be in my head. And if it's all in my head, I'll be back on the board asking for some anti-hallucinogens instead of asking for mechnical advice!
 
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Squibb

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You can always test the brake for efficiency on a car type brake test roller. It is very difficult to test floating discs for run-out, even with a dial gauge.
 

Wheelin

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You can always test the brake for efficiency on a car type brake test roller. It is very difficult to test floating discs for run-out, even with a dial gauge.
So does that mean I would need to take my bike to professional garage, because that's what the pictures look like. (You're probably accurately guessing that I'm new to this stuff.)
 
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