Tā kāihuì shí zǒng ài fàng kōngpào, méi yí cì luòshí de.
He's always full of big talk at meetings — not one promise actually gets carried out.
Tips
usage
Compare 放大炮 (talk big, make loud attacks) vs 放空炮 (make empty promises, no follow-through). 放空炮 specifically emphasizes that the words never turn into action.
memory
A 空炮 is a blank shell — lots of bang, zero impact. Perfect image for someone whose words don't lead anywhere.