how can i tell my brakes are bad i have a noise coming from the front left and i think it could be like i mention in another thread the akle bearing or inner tire rod but lets say its the brakes how do i do this
The best way to check the brakes is to remove the wheel. Look inside the 'window' on top of the caliper. Use a flashlight and look to see if the brake pad is worn down close to the metal part of the pad. A brand new brake pad should have about 3/8" of pad material. If you can't see the pad, then you may have to take the pads out of the caliper. You may also want to check the rotor to see if it is warped. Warping can occur if the lug nuts are not torqued to the proper specs.
If you don't have a service manual for the car. You may want to purchase one on eBay or buy a Haynes manual for the Nissan Sentra. Either on will give you a good step by step instruction on this subject.
Hope this helps.
How many miles have you put on the car since the pads were changed?