light braking = high pitch sound
 

So I'm driving my mom's 2012 corolla.
During city driving, when applying light braking it'll produce a high pitch screeching sound...
My gf says brakes should be oiled from time to time; I didn't know brakes need to be oiled...
My questions:
how do I check how much brake I have left?
if the brakes are fine does that mean they need to be oiled?
what brands of oil are cheap and gets the job done?
how to apply brake oil?

sorry lots of questions, but thanks for anyone that can help

Your car probably needs some brake quieter. Take it to a shop and get a brake inspection if you want to know how much life is left. Some shops offer brake inspection with oil changed down at richmond. Sometimes if your brakes screech it coupd indicate that it's time to change your pads.

Google: How to change brake pads

Read articles and watch a few "how to" vids.

No, they don't need oil.

What he said^^ Could also be a rock stuck in there.

thanks for the insights guys!

Don't ever oil your brake (pads), they will cause your car to have spongy braking.
I think shes prob referring to brake fluid? ,but even that should not be the cause for this case.
Best and safest bet is to bring it to a shop for inspection :)