what is the electr unit on top of my brake pedal , i acc.broke it.no more brakes

What is your question?

its about 2 inch by 2 inches its mounted and wired to pedal. the other day i noticed a lil black electric box on floor .. truck was same. i after losing the brakes looked at pedal and noticed there was two lil copper contacts with a what appears to be the missing peice.. which is missing ..{Please help me out. thanks a bunch