17 00 009 Checking cooling system for watertightness

WARNING: This page is about a different car, the 2017 MINI Cooper, 2016 MINI Cooper, 2015 MINI Cooper, and 2014 MINI Cooper. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

WARNING: Risk of burning! Only carry out repair work on the cooling system after the engine has cooled down! Wear hand protection and safety goggles.

IMPORTANT: Open cooling system only when it has cooled down.
Opening the cooling system while hot can result in air entering the system.
This can cause overheating with permanent damage to the engine!

Necessary preliminary tasks:

Follow all notes for carrying out REPAIR WORK ON THE COOLING SYSTEM .

Checking pressure drop in cooling system:

Unscrew sealing cap from coolant filler neck.

Connect special tool 17 0 109 to the coolant filler neck.

Connect special tools 17 0 102 and 17 0 101 .

Build up EXCESS PRESSURE and wait approx. 2 minutes.

Cooling system is tight if pressure drop does not exceed 0.1 bar.

Fig 1: Checking Pressure Drop In Cooling System

Courtesy of BMW OF NORTH AMERICA, INC.

Checking pressure relief valve in sealing cap:

NOTE: While the driving at high ambient temperatures, the design may cause the pressure relief valve in the sealing cap to open slightly and air together with dissolved coolant to escape. This coolant vapor condenses on the surface of the expansion tank and leaves traces of coolant after the vehicle has cooled down. These coolant traces do not indicate whether the cap is defective or not. When the vehicle has been parked up for an extended period of time, the residual escaping coolant can cause the pressure relief valve in the sealing cap to stick; therefore check the sealing cap again 2 to 3 times.
Replace the sealing cap only after you have checked three times and there is an incorrect opening pressure .

Checking pressure relief valve in sealing cap:

Screw on sealing cap (1) on special tool 17 0 115 from the set of special tools 17 0 100 .

Use special tool (hand pump) 17 0 101 from the special tool set 17 0 100 to build up pressure; observe pressure gauge to ascertain when opening pressure is achieved.

Compare opening pressure of PRESSURE RELIEF VALVE .

Fig 2: Checking Pressure Relief Valve In Sealing Cap

Courtesy of BMW OF NORTH AMERICA, INC.