Yes, PULLBACK is a Scrabble word!

Letter values in Scrabble US: P 3, U 1, L 1, L 1, B 3, A 1, C 3, K 5.

Is it a valid word?

PULLBACK is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a device (as a decorative loop of cord or fabric) for holding or drawing something back
(military) the act of pulling back (especially an orderly withdrawal of troops)