Ramp up case cracked after deadline (8)
I believe the answer is:
escalate
'ramp up' is the definition.
(I've seen this before)
'case cracked after deadline' is the wordplay.
'cracked' indicates an anagram.
'after deadline' becomes 'late' (I've seen this in another clue).
'case' is an anagram of 'esca'.
'esca'+'late'='ESCALATE'
(Other definitions for escalate that I've seen before include "Raise to higher level, perhaps war" , "mushroom" , "Magnify" , "rocket" , "Intensify" .)