I like to think that every time I hit something with my spanner, I'm hitting a specific part, like a tuner for the engines, and those things take a while to pop out again. When they don't pop out again, they're full.
With bigger items, bigger and more important parts are stabilized per swing. However, these larger, more studier parts take time to pop out again before they can be interacted with.
This is also a key part as to why repairing with such a weak tool such as the spanner is important. The large parts require heft in order to push and repair, taking a while to push with the unwieldy mallet and wrench, while the small parts can be quickly adjusted and fabricated for mid-combat use.
Alright, now to shift out focus to more tools than just repair.
Why can't someone repair something that's been chemsprayed 3 seconds ago, and vice-versa?