My front disc brake is rubbing. I watched a couple of videos on how to fix it, so far I have:
Loosened the mounting points, squeezed the brake, and tightened the mounting points—doesn’t change anything.
Taken the brake pads out and pushed back on the pistons to reset them. This fixes the issue (i.e. the wheel spins freely), but then when I pull the brake, the problem comes back.
I have had this bike for 14 months; wondering if it is time to bleed the brakes? Or is there another fix I am missing? Rotor does not appear to be warped at all.
by theworldtonight
12 Comments
>I have had this bike for 14 months; wondering if it is time to bleed the brakes?
If you have to ask … 😉
new bike
In addition to a bleed, you may need to work on the calipers to clean and grease the pistons. If you do both I’m pretty sure you’ll be good to go.
There’s at least a chance your caliper isn’t aligned properly, or that the disc is bent. Brake bleeding is great and all, but doubtful that’s your total solution.
You got “lazy calipers”. The brake and the outer piston area needs proper cleaning. The piston can’t move freely along the seal.
Sometimes one can clean the dirt/grime with q-tips (soaked with methanol) off, sometimes the brake needs to be disassembled.
As you write about 14 month, you might be lucky to fix it with a proper cleaning.
Check online about “lazy brake piston”.
Before you bleed, try this…
[piston massage](https://youtu.be/HaNINyOcmJI?si=3gw_k3C6nRnyjVNv)
Working the pistons back and forth multiple times with as much travel possible is a great way to get back the full motion of the piston.
Don’t grease or lube the exposed position. It will collect dirt and other contaminants, as well as prevent the square cut piston seal from properly retracting the piston.
Pretty much every manufacturer tells you to NOT grease or oil the piston.
You can clean it, but don’t lube it.
That being said, 14 months is long enough of a time frame to necessitate a bleed.
I just rode mine, it made noise for like 30km but I just took the extra resistance as a workout. It has been fine ever since.
Please return the bike and demand a refund!
Sometimes you have to manually align the caliper. Loosening the bolts and squeezing doesn’t always work on brakes like that. The mounts aren’t always perfect, hardware can be imperfect plus the brake hose pushed the caliper at weird angles.
Look through the caliper, you want to see light on both sides of the disc. Loosen the bolts, hold the caliper in alignment and tighten. It can be tricky. Sometimes you can fully loosen one bolt and keep one slightly snug. Then you adjust the loose one, snug it down, loosen the other, adjust and snug then tighten both. Often the caliper will want to move when you tighten the bolts. It can be pretty difficult depending on the bike.
Good luck!
Have any of you had the loose bolts squeeze the lever thing ACTUALLY work? I have that ‘work’ maybe 1/100 times and when it does it’s still never centered. With our without the purple Hayes tool.
Aligning manually is the only thing that truly works 100% of the time
Guys. Please. He just needs to align it properly. Check rotor true ofc, but this isn’t that big of an issue…
Could be everything, BUT my big suggestion is get a piston press tool
[Amazon piston press tool](https://www.amazon.com/MIEBA-Shimano-Bicycle-Compressor-Universal/dp/B0DBQSWPXZ/ref=sr_1_3_sspa?adgrpid=188868427560&dib=eyJ2IjoiMSJ9.QOnGIAt01sRatpliRSMM3c6IX-geWDKijAiZ1-MvMEoqI38u6aFvjiL_3B391z-cJvLPV-gh26vIq8WQd3tjFPtDl2sUWL4wiJegqn6cnHNd3-DC1M5Dxrhd1bpjY3Yq1TSTYKq9LuFt5Mi-k4niFP9O9M2Wtd_-_zSR8xUEIzEZhk7-ll2RjsjqlWCHwz-j0wnwfOQZn9ViXeaeNkCeA-H2fhaSMzh90odzBnbsPiXYfpe_69MMpxLixpnXmeDqw8SdAug3YMFqoodRxb98Nbwik1Cp3Gjgt2IirRKoeiA.2UoI8I1w_VaxTAVWEG_yiyzRTYYgMOG5-ReOSPgpy7c&dib_tag=se&hvadid=779670702188&hvdev=c&hvexpln=0&hvlocphy=9060354&hvnetw=g&hvocijid=8338597935716986371–&hvqmt=b&hvrand=8338597935716986371&hvtargid=kwd-354216590127&hydadcr=7512_13589609_67577&keywords=brake+pad+spreader+tool&mcid=e0e5713aa49438e0af491e8910467ddd&qid=1771429363&sr=8-3-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1)
$18
Resetting your pistons fully can be tricky since they can gum up. I would take out the wheel and pads and slightly press out the pistons and then liberally clean with rubbing alcohol. Then take this tool and completely reset the pistons.