I'm thinking semantics too, at least when talking car parts. According to Bing they're interchangeable for that purpose.
re·place
[rəˈplās]
VERB
take the place of.
"Ian's smile was replaced by a frown"
provide or find a substitute for (something that is broken, old, or inoperative).
"the light bulb needs replacing"
synonyms:
substitute · exchange · change · give in place of · [more]
fill the role of (someone or something) with a substitute.
"the government dismissed 3,000 of its customs inspectors, replacing them with new recruits"
synonyms:
take the place of · succeed · be a replacement for · [more]
put (something) back in a previous place or position.
"he drained his glass and replaced it on the bar"
synonyms:
put back · return · return to its place · restore
in·stall
[inˈstôl]
VERB
place or fix (equipment or machinery) in position ready for use.
"we're planning to install a new shower"
synonyms:
put · position · place · put in place · set in place · fix · fit · locate · [more]
load (software) into a computer.
"you may want to install a new version of the program"
place (someone) in a new position of authority, especially with ceremony.
"he was installed as music director at the Cathedral of St. Barbara in Cracow"
synonyms:
swear in · induct · instate · inaugurate · invest · institute · introduce · [more]
establish (someone) in a new place, condition, or role.
"Ashley installed herself behind her table"
synonyms:
ensconce · establish · position · settle · seat · lodge · plant · [more]