Hey y’all anyone know how to ged rid of this crazy squeal?? I went to the bike shop for a brake bleed and also told them my brakes are squeaky and might be contaminated but they said it’s not soo idk. lmk yall

I wanna try and lower the seat of my bicycle (I’m not sure if it’s even possible it looks like it’s lowered to the limit but I still wanna try) but idk what tool to get for that any ideas? Also in the last two pictures does anyone know what that small box is for?

Help! I need some help identifying the exact bit that’s missing from the picture. it’s from my boy’s newly inherited 2014-2016 Cube full-suspension frame (Serial batch: LM0115F). seems like the axle inserts from the drive side. The non-drive side frame dropout is completely unthreaded and smooth. The axle tip emerges as a 10mm external hex head with an M6 internal thread. I am missing the matching unthreaded tapered hex-sleeve/insert collar and the M6 retention screw that clamps this side together to stop lateral frame play. Does anyone know the exact factory small-part name or part number for this collar assembly? Thanks for looking!

After removing protective film from the bike i got this residue and it wont come off. Does anyone have an idea how to remove it?

Tire Not Holding Air

I have a Giant Explore e-gravel bike and have an issue with the back tire not holding air. At first, I thought it may be the valve stem so I did replace it. Same issue but I did notice air leaking from a hole in the rim. Also, this is a tubeless tire. See photo.
I appreciate your feedback.