go down vs break down

go down and break down both are verbs.

Word	Noun	Adjective	Verb	Adverb
go down	No	No	Yes	No
break down	No	No	Yes	No

As verbs, break down is a hypernym of go down; that is, break down is a word with a broader meaning than go down:

Other hypernyms of go down include break, conk out, die, fail, give out, give way, go, go bad.

go down (verb)	break down (verb)
grow smaller	collapse due to fatigue, an illness, or a sudden attack
stop operating	stop operating or functioning
be defeated	separate (substances) into constituent elements or parts
be ingested	make a mathematical, chemical, or grammatical analysis of; break down into components or essential features
go under	make ineffective
disappear beyond the horizon	cause to fall or collapse
move downward and lower, but not necessarily all the way	lose control of one's emotions
be recorded or remembered	fall apart