Checking Pressure Relief Valve In Cap:

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Detach rubber (1) from hand pump. Attach special tool 17 0 007 / 17 0 008.

Fig 1: Detaching Rubber From Hand Pump

Courtesy of BMW OF NORTH AMERICA, INC.

Screw cap (1) onto special tool.

Build up pressure with special tool (hand pump) 17 0 002; observe pressure gauge to ascertain when opening pressure is achieved.

Compare opening pressure of pressure relief valve.

Fig 2: Screwing Cap Onto Special Tool

Courtesy of BMW OF NORTH AMERICA, INC.