Jason56258

I just received an ebike and the hydraulic discs brakes have been an issue. I have trued the rotor so it does not rub but I still have a squeak. It squeaks with no brakes applied and the squeak goes away when I remove the calipers. No matter how I adjust the calipers this squeak will not go away.

Barry2 

Do the rotors rub when you spin the wheel by hand ?
Do the rotors rub when you ride the bike?
If you retract the pistons and test the above, what happens then ?

Barry

oh, and welcome to bike forums

Jason56258

Hi barry, the rotors don't rub when I spin the wheel or ride. Just this annoying squeak. It sounds just like rubbing two pieces of rubber together. The only thing that I noticed is the rotor is not dead center of the wheel. And that's the next thing that I was going to loosen and try. But when I look with a flashlight it looks like there's clearance everywhere.

2old

If it squeaks with no brakes applied, there's a rub in the system. Let the dealer solve the problem for you, unless it's a behemoth from China, then maybe change the brakes (Amazon has excellent Shimano 200's for <$60 a pair; I purchased them, and although they may be knock-offs, they function perfectly).

Barry2 

However you state removal of the brake calipers stops the squeak.
which brake caliper, front or rear ?

Jason56258

Front

Barry2 

If you leave the caliper in place but remove the front brake pads, then what happens?
DON'T SQUEEZE THE BRAKE WITH HE PADS OUT, YOU'LL POP A PISTON!

Jason56258

Now I feel stupid 🤦🏼‍♀️ for the second time I removed the calipers and spun the wheel and it squeaks. Why It didn't do it the first time I have no idea 🤔 It must be a bearing 🙄.

FBinNY 

If the bike has a suspension fork, it will move when loaded. If there's some slop, that could be enough to move the caliper over, or for the wheel tilt if one strut rises more than the other.

Either way, your perfectly centered brake will now be rubbing very slightly.

If so, or maybe, recruit a friend to sit on the bike while you check if the c a liner is still centered. If not buy your friend a treat and keep him there while you adjust the brake.

Jason56258

I just had a chance to go out there and look at it some more. Now when I pull the caliper off the squeak remains. Why It didn't do this the first time I don't know. I wish it would have, it would have saved me a lot of time and pondering. It must just be a bearing. Wonder if the squeak would go away after a while or if it would continue to get worse

FBinNY 

The one thing it most likely is not is a bearing.

Since you say it sounds like rubber, it just might be.

Most likely is hub/axle seals if it syncs to wheel speed. If random, consider the suspensions boots, or something within.

Once you have a suspect, put a drop of oil where thecseal slides, and allow b it to weep in with movement.

Jason56258

thank you. It was the hub/axle seals. I never would have thought of that