brake fluid AUDI A4 1996 B5 / 1.G Hydraulic Changing And Bleeding Fluid Workshop Manual

47-23


Brake hydraulic system,
bleeding and changing brake
fluid

WARNING!

Brake fluid is poisonous.

It must NEVER be removed by siphoning
with your mouth.
If brake fluid contacts skin or eyes, flush or
wash adequately to prevent irritation. Get
medical attention immediately if necessary.
Brake fluid must be disposed of properly in
compliance with environmental regulations.

CAUTION!
Do not allow brake fluid to mix with liquids
that contain mineral oils (e.g. motor oil,
cleaning agents). Mineral oils damage the
plugs and seals in the brake hydraulic
system.
Brake fluid must not be allowed to come into
contact with paintwork due to its caustic
effect.
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Brake fluid is hygroscopic, in other words it
absorbs moisture from the surrounding air,
and must therefore always be stored in
airtight containers.
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Note:

Only use new brake fluid conforming to US
standard FMVSS 116 DOT 4.
Genuine VW/Audi brake fluid conforms to this
specification.
Rinse off any spilled brake fluid using plenty of
water.
When the system is open do not work with
compressed air and do not move the vehicle.
During the final road test, make sure at least
one ABS-controlled braking operation is carried
out (normal pulsations must be felt at the brake
pedal).

Bleeding using US1116 brake bleeder

- Connect US1116 brake bleeder.

- Open bleeder screws in following sequence and
bleed brake calipers.

Bleeding sequence

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Brake fluid, changing (every two years)


WARNING!

Brake fluid is poisonous.

It must NEVER be removed by siphoning
with your mouth.
If brake fluid contacts skin or eyes, flush or
wash adequately to prevent irritation. Get
medical attention immediately if necessary.
Brake fluid must be disposed of properly in
compliance with environmental regulations.

CAUTION!
Do not allow brake fluid to mix with liquids
that contain mineral oils (e.g. motor oil,
cleaning agents). Mineral oils damage the
plugs and seals in the brake hydraulic
system.
Brake fluid must not be allowed to come into
contact with paintwork due to its caustic
effect.
Brake fluid is hygroscopic, in other words it
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yp
e=re
pair&id=AUDI.B5.SU03.47.5

47-26

Note:

Only use new brake fluid conforming to US
standard FMVSS 116 DOT 4.
Genuine VW/Audi brake fluid conforms to this
specification.
Rinse off any spilled brake fluid using plenty of
water.
When the system is open do not work with
compressed air and do not move the vehicle.
During the final road test, make sure at least
one ABS-controlled braking operation is carried
out (normal pulsations must be felt at the brake
pedal).

Repair Manual, "ABS/EDL/ASR On Board
Diagnostic (OBD)," Repair Group 01

Changing brake fluid using US1116 brake
bleeder

- Open brake fluid reservoir.
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Note:
The brake fluid reservoir must be kept
adequately filled to prevent air from entering the
brake system through the reservoir.

- With engine running and bleeder screw on right-rear brake caliper
open, use brake pedal to pump brake fluid out of reservoir until level
goes down as far as opening for hydraulic clutch supply hose.
- Collect used brake fluid in suitable container, then close bleeder screw.
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CAUTION!

Always dispose of used brake fluid properly.

On vehicles with manual transmission, the
clutch slave cylinder must also be flushed
out with new brake fluid.
On models with the electronic Stability
Program (ESP), note that the hydraulic pump
is actuated for 10 seconds using "Basic
Settings" function 04, display group 002
page 45
-49
.
Note the following when bleeding clutch
hydraulics:

- Connect US1116 but do not switch on yet.

- Open bleeder screw on clutch slave cylinder.

- Attach collector bottle hose.

- Switch on bleeder unit and allow approx. 100 cc
(6 oz.) of brake fluid to flow out of clutch slave
cylinder.

- Close bleeder screw.
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- Attach bleeder hose from brake fluid collector to
bleeder screw.

- Open bleeder screw and allow about 250 cc (15
oz.) of brake fluid to drain out.
The action of pumping in new brake fluid flushes
the used brake fluid out of the system.

- Close bleeder screw.

- Check brake pedal pressure and pedal free
play.

Max. free play: 1/3 of pedal travel.
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