ID.4 2021 ➤, ID.5 2021 ➤
Maintenance - Edition 11.2021
4.10
Brake system and shock absorbers: in‐
specting for leaks and damage
Check following components for leaks and damage:
♦ Brake master cylinder
♦ Brake servo (for anti-lock brake system: hydraulic unit)
♦ Brake pressure regulator and
♦ Brake caliper
♦ Shock absorbers (during inspection only)
♦ Presence of dust caps on brake fluid bleeder screws
♦ Presence of caps on guide bushes
– Ensure that brake hoses are not twisted.
– Additionally ensure that brake hoses do not touch any vehi‐
cle components when steering is at full lock.
– Check brake hoses for abrasion, porosity and brittleness.
– Check brake lines for corrosion.
– Check brake connections and fastenings for correct seating,
leaks and corrosion.
– Check brake lines and brake hoses for correct seating and
attachment in retainers.
Note
Faults found must always be rectified (repair measure).
4.11
Brake fluid level: checking
CAUTION
Risk of skin injury from corrosive brake fluid.
Risk of irritation and injury to skin.
– Avoid contact with the skin.
NOTICE
Risk of damage to vehicle from corrosive brake fluid.
Possible damage to paintwork and vehicle.
– Avoid contact with components and paintwork and if nec‐
essary rinse off any spilt brake fluid with water.
NOTICE
Risk of damage to brake system if brake fluid is used incor‐
rectly.
Mineral oils damage plugs and sleeves of the brake system.
– Do not mix fluids containing mineral oil (oil, petrol, cleaning
solution) with brake fluid.
4. Descriptions of work
37
ID.4 2021 ➤, ID.5 2021 ➤
Maintenance - Edition 11.2021
NOTICE
Brake fluid is hygroscopic, which means it absorbs moisture
from the ambient air.
If the water content in the brake fluid is too high, the brake
system could fail, and it promotes corrosion within the brake
system.
– Store brake fluid in air tight containers.
Brake fluid level at delivery inspection
– At delivery inspection, the fluid level must be at MAX. mark‐
ing -1-.
Note
To prevent brake fluid from flowing out of the reservoir, the
MAX. marking -1- must not be exceeded.
Brake fluid level during inspection
Note
♦ The fluid level must always be judged in conjunction with
lining/pad wear.
♦ When vehicle is in use, fluid level tends to drop slightly due
to lining/pad wear and automatic adjustment.
Recommended brake fluid level “before” brake pads are at wear
limit
•
At MIN marking or just above -2-
“replenishing is NOT required”.
38
4. Descriptions of work
ID.4 2021 ➤, ID.5 2021 ➤
Maintenance - Edition 11.2021
Recommended brake fluid level, brake pads new or well within
wear limit:
•
Between MIN and MAX markings
Note
If the fluid level is below MIN. marking -2-, the brake system
must be checked for leaks before fluid is topped up, “Repair
measure”.
4.12
Front brake discs and rear drum brake
pads: checking thickness of pads and
condition of discs
Front disc brake pads: checking thickness ⇒ page 39
Rear drum brake pads: Checking thickness ⇒ page 40
Brake discs: checking condition ⇒ page 41
Special tools and workshop equipment required
♦ Torque wrench
♦ Battery lamp -VAS 6901-
♦ Mirror
The adapter to loosen and tighten the anti-theft wheel bolts can
be found in the vehicle tool kit ⇒ page 51 .
4.12.1
Front disc brake pads: checking thick‐
ness
Note
One some vehicles it may be very difficult to ascertain or meas‐
ure the thickness of the pad due to the geometry of the wheel
rim. If this is the case, remove the wheel on the side where
the brake pad wear indicator is installed for better evaluation or
measurement of the remaining pad thickness.
Procedure
– Measure outer and inner brake pad thickness by inspecting
through the holes of wheel rim (depending on type).
– For better evaluation or measurement of remaining pad
thickness, remove wheel on side where brake pad wear indi‐
cator is installed as necessary.
– Pull off wheel bolt covers if necessary ⇒ page 51 .
4. Descriptions of work
39
2024 VW ID.4 Owner's Manual
