The answers to the clues below are familiar expressions - but with something added. 

1. Midweek special at the diner

2. Top 40 at the college radio station 

3. Remain loyal

4. Aviator show signs of receding

5. "Let's Make a Deal" creator and no one else

Answers:

 

The "something" added is the letter H at the front of the first word in each expression.

 

1. HASH WEDNESDAY

2. HITS ACADEMIC 

3. HOLD FAITHFUL

4. HAIRLINE PILOT

5. HALL OR NOTHING

 

Credit:
Fred Piscop (#1-4)

WHAT THE H?