NHC MOTORS · SERVICE RECORD
BMW 740Li coolant leak: hose replacement and cooling-system care
Is topping up enough when coolant keeps falling? A noticeable loss in a closed cooling system needs investigation. This 2016 BMW 740Li received a new coolant hose, BG cooling-system cleaning, then NorthSea Glacier Antifreeze XL coolant and BG Super Cool.
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Coolant-hose replacement
We replaced a coolant-line hose as part of the leak work. The removed hose and replacement were compared before installation.
Rubber hoses age under repeated heat and pressure. A leaking component needs repair or replacement; repeated top-ups do not resolve the source.
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BG cooling-system cleaning
BG cooling-system cleaning accompanied the hose work. The existing coolant and contamination were assessed as part of preparing for the fresh fill.
NorthSea Glacier Antifreeze XL coolant and BG Super Cool supplementary treatment were prepared for filling.
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Coolant refill and BG Super Cool
Dedicated equipment was connected to fill the cooling system. It helps reduce trapped air, with bleeding managed as part of the procedure.
BG Super Cool was added during the refill. Our coolant guide explains maintenance, and the BMW 520d coolant-leak case provides another example of leak inspection.
Related maintenance reading
Related workshop video
Related workshop example: BMW 5 Series coolant-leak repair.
BMW 5 Series coolant leak while driving · Watch on YouTube →Questions before booking
What should I do if coolant keeps disappearing?
A noticeable drop in a closed cooling system calls for a leak inspection. Locate the source and repair the affected component rather than repeatedly topping up.
Why clean the cooling system when replacing a hose?
The repair and existing coolant condition determine the scope. This 740Li received BG cleaning alongside hose replacement before fresh coolant was added.
What should I do if an overheating warning appears while driving?
Continued driving while overheated can damage the engine. Stop promptly in a safe place and arrange inspection.
Coolant loss: start by locating the source
We inspect the cooling system to identify where work is needed. If you have been relying on top-ups, contact us to arrange an inspection.
We explain the work and cost before proceeding with your agreement.
Call about servicingBook through Naver031-258-1617 · NHC Motors, Gwonseon-gu, Suwon · By appointment