Hi I recently bought a Nissan Sentra 2018, it was crashed and I repaired it, which has been a pain in the ass but it's almost completed, however I have an issue; when I hit the brake pedal it shakes a lot; specially when it gears into reverse, I discovered that the break fluid container shakes aswell (someone helped me check with my hood open) when they hold that container it doesn't shake anymore and the vibration on the pedal stops as if that's where the vibration is coming from; I already changed the engine and transmission mounts so that wasn't the source of the vibration (they were absolutely destroyed aswell btw); I would appreciate if you can enlighten me as to what the problem might be; thanks anyway and I love your videos!!!
Sounds like you bought a car that you probably shouldn't have, unless it was practically free and you wanted a project. It takes a ton of energy to break motor mounts and transmission mounts in a crash. Unibody cars are practically impossible to repair correctly after a collision like this, they crush like soda cans.
The brake fluid "container" you're referring to sits on top of the master cylinder, which is the heart of the braking system. It's mounted on a large, cylindrical object on the firewall, that's the power brake booster. The assembly should not move at all. Make sure your bolts are tight holding the booster on the firewall, and that the bolts holding the master cylinder are tight. There's no real reason for that to shake when the car's just sitting there, not moving.
Make sure the motor mounts and transmission mounts are properly torqued. Vibrations from improperly torqued, poorly aligned, or poorly positioned mount as a result of the accident could cause the master cylinder to shake as they travel through the car.
