When beers tip over, take a break! (3,4)
I believe the answer is:
pit stop
'when beers' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.
'tip over take a break' is the wordplay.
'over' says the letters should be written in reverse.
'take a break' becomes 'stop' (I've seen this in another clue).
'tip' backwards is 'pit'.
'pit'+'stop'='PIT STOP'
Can you help me to learn more?
(Other definitions for pit stop that I've seen before include "place where car can be serviced - with 31a" , "part of the race" , "period of service?" , "Break during motor race" , "F1 race feature" .)