Check The High-Temperature Cooling System For WATERTIGHTNESS

WARNING: Hot surfaces. 
Risk of burning! 

• Perform all work only on components that have cooled down.

• Loosen sealing cap (1).

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• Attach the special tool 0 494 418 (17 0 101)  with special tools 0 494 419 (17 0 102)  and 0 494 426 (17 0 109)  from the set of special tools 0 494 417 (17 0 100). 
• Build up excess pressure and wait for approximately 2 minutes.

  Courtesy of BMW OF NORTH AMERICA, INC.

  TECHNICAL DATA SPECIFICATION
  
  

  Opening pressure of sealing cap of high-temperature coolant circuit
  	Pressure relief valve opens when the pressure exceeds the ambient pressure.	min. 1.4 bar
  	Electric changeover valve must open at latest when the pressure is lower than the ambient pressure	max. 0.1 bar
  	Test pressure for cooling system (gauge pressure)	1.5 bar

  NOTE: TECHNICAL INFORMATION 
  If the described test step is not completed successfully: repeat test step twice. Only replace the sealing cap after three tests with an incorrect opening pressure. 
  When driving at high ambient temperatures, the design may cause the pressure relief valve in the sealing cap to open slightly and air to leakage together with dissolved coolant. This coolant vapor condenses on the surface of the coolant expansion tank and leaves traces of coolant when the vehicle has cooled down. These traces of coolant do not indicate whether the sealing cap is defective or not.
  Leakage coolant vapors when the vehicle is at standstill may cause the pressure relief valve to stick to the sealing cap. This may cause an incorrect opening pressure.

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• Screw on sealing cap (1) on special tool 0 494 643 (17 0 114)  from the set of special tools 0 494 417 (17 0 100). 
• Build up the pressure with special tools 0 494 418 (17 0 101)  and 0 494 419 (17 0 102)  from the set of special tools 0 494 417 (17 0 100). 
• Observe on the pressure measuring device when the opening pressure has been reached.
  TECHNICAL DATA SPECIFICATION
  
  

  Opening pressure of sealing cap of high-temperature coolant circuit
  Pressure relief valve opens when the pressure exceeds the ambient pressure.		min. 1.4 bar
  Electric changeover valve must open at latest when the pressure is lower than the ambient pressure		max. 0.1 bar
  Test pressure for cooling system (gauge pressure)		1.5 bar

• Close sealing cap (1).
• Close the sealing cap (1) until the arrows  are flush.

Courtesy of BMW OF NORTH AMERICA, INC.