163 589 01 91 00 Test cap - WS20.00-P-0023B

FG 20/Set B 

MODEL 163, 211, 230 

Use: 

Test cap for coolant expansion reservoir in combination with tester 124 589 24 21 00

Inspect cooling system for leaks

Fig 1: Identifying Test Cap (163 589 01 91 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.