Refill only with distilled water. All other types of water can cause corrosion in the engine due to
the chemical components contained in the water. This can also lead to engine failure. If any other
type of water apart from distilled water has been refilled, the fluid in the cooling system should be
completely replaced immediately by a qualified workshop.
⇒ Fig. 188 . Otherwise the excess coolant will
be forced out of the cooling system when the engine is hot and could cause damage.
completely. Heavy coolant loss is an indication of leaks in the cooling system. The cooling system
should be checked by a qualified workshop as soon as possible. Failure to do so can result in engine
damage.
have entered the cooling system. Do not drive on! Seek expert assistance. Failure to do so can result
in engine damage.
correct openings. The use of incorrect service fluids could result in serious malfunctions and engine
damage.
Brake fluid
Fig. 190 In the engine compartment: cap on the brake fluid reservoir.
Brake fluid will gradually absorb water from the surrounding air over the course of time. The brake
system will be damaged if there is too much water in the brake fluid. The boiling point of the brake
fluid is also considerably reduced by the water content. Heavy use of the brakes and full braking may
cause a vapour lock in the brake system if the water content is too high. Vapour locks reduce levels
of braking power, considerably increase braking distance and can even cause the brake system to fail
completely. Your own safety and that of other road users depends on having a brake system that
functions properly at all times ⇒ .
Brake fluid specification
Volkswagen has developed a brake fluid that has been optimised for the brake system in the vehicle.
To ensure optimal operation of the brake system, Volkswagen expressly recommends the use of
brake fluid compliant with VW standard 501 14.
Before using a particular brake fluid, check that the brake fluid specifications printed on the
container correspond to the vehicle requirements.
Brake fluid that is compliant with VW standard 501 14 is available from Volkswagen dealerships.
If this brake fluid is not available and it is necessary to use another high-quality brake fluid instead,
brake fluid that is compliant with DIN ISO 4925 CLASS 4 or US standard FMVSS 116 DOT 4 can be
used.
Not all brake fluids that are compliant with DIN ISO 4925 CLASS 4 or US standard FMVSS 116 DOT 4
have the same chemical composition. Some of these brake fluids may contain chemicals that can
damage or destroy brake system components over time.
Volkswagen therefore recommends the use of brake fluid that is compliant with VW standard 501 14
to ensure sustained proper operation of the brake system.
Brake fluid that is compliant with VW standard 501 14 fulfils the requirements of DIN ISO 4925
CLASS 4 or US standard FMVSS 116 DOT 4.
Brake fluid level
The brake fluid level must always be between the MIN and MAX marking on the brake fluid reservoir
or above the MIN marking ⇒ .
The brake fluid level cannot be checked accurately in all models as engine components may partially
conceal the fluid level in the brake fluid reservoir. If the brake fluid level cannot be read exactly,
please go to a qualified workshop.
The brake fluid level drops slightly during vehicle operation as the brake pads wear and the brakes
are automatically adjusted.
Brake fluid level
The indicator lamp lights up red.
Brake fluid level is too low.
Do not drive on! Check the brake fluid level.
If the brake fluid level is too low, inform a qualified workshop. Have the brake system checked.
Changing the brake fluid
The brake fluid should be changed by a qualified workshop. Volkswagen recommends using a
Volkswagen dealership for this purpose. Only brake fluid that conforms with the required
specification should be used.
WARNING
Brake failure or reduced braking efficiency can be caused by the brake fluid level being too low or by
brake fluid that is too old or unsuitable.