brake AUDI A4 1998 B5 / 1.G Rear Calipers Workshop Manual

47-13


Rear brake calipers, servicing WARNING!
Note:
Do not re-use fasteners that are worn or
deformed in normal use.
Some fasteners are designed to be used only
once, and are unreliable and may fail if used
a second time. This includes, but is not
limited to, nuts, bolts, washers, circlips and
cotter pins. Always follow recommendations
in this manual-replace these fasteners with
new parts where indicated, and any other
time it is deemed necessary by inspection.
Install only the complete repair kit when
performing servicing work.
Apply a thin coat of assembly paste to brake
cylinders, pistons and seals.
1 -
Self-locking bolt
Always replace35 Nm (26 ft lb)Counter-hold guide pin when loosening
and tightening
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2 -
Brake caliper housing
Replace caliper if leaks appear at lever for
parking brake cable After servicing, pre-bleed brake caliper
housing Fig. 6

1997 aluminum brake calipers are
installed Servicing aluminum brake calipers page 47
-19

3 -
Bleeder valve
4 -
Dust cap
Install on bleeder valve
5 -
Seal Use 3409 wedge to remove Fig. 3
6 -
Piston
With automatic adjuster for parking brakeRemoving from brake caliper housing
Fig. 1

Installing into brake caliper housing Fig. 5 Servicing aluminum brake calipers page 47
-19

7 -
Guide pin
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Grease before installing the protective boot
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8 -
Protective seal
Install with outer sealing lip on piston
Fig. 2

Insert inner sealing lip into groove in brake
caliper housing Fig. 4

9 -
Protective boot
Install on brake carrier and guide pin
10 -
Brake carrier With guide pins and protective bootsSupplied as a pre-assembled replacement
part with an adequate quantity of grease on
the guide pins Install repair kit if protective boots are
damaged Use grease supplied with repair kit for
greasing the guide pins
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Fig. 1 Unscrewing piston from brake caliper housing using 3272
reset and screwout tool

Fig. 2 Installing protective seal with outer sealing lip onto piston
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Fig. 3 Use 3409 wedge to remove seal

Note:
Hold piston in front of the brake caliper housing when performing this
step. Fig. 4 Inserting inner sealing lip of protective seal into groove in
brake caliper housing using 3409 wedge
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Note:
The outer sealing lip of the protective seal will then locate in the piston
groove. Fig. 5 Turning piston into brake caliper housing until fully seated
- When screwing in, press firmly on the piston.

Note:
Position brake caliper upright for pre-bleeding, as shown. Fig. 6 Pre-bleeding brake caliper
- Open bleeder valve and fill with brake fluid, using commercially
available bleeder bottle, until brake fluid flows out of threaded hole
(brake hose connection) free of bubbles.
- Close bleeder valve.
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47-19

Aluminum rear brake caliper pistons,
removing and installing


Special tools and equipment
3409 wedge3272 reset and screwout tool3272/1 support plate

Unscrewing piston from the brake caliper housing
- Remove piston by turning threaded spindle -A- counterclockwise and
knurled section -B- clockwise.
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47-20


Installing protective seal with outer sealing lip over piston

Removing seal using 3409 wedge
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47-21


Installing inner sealing lip of protective seal using 3409 wedge
Note:
Hold the piston in front of the caliper housing for this procedure.

Turning piston into brake caliper housing to stop
Note:
The outer sealing lip of the protective seal will then locate in the piston
groove. - Turn piston in by turning threaded spindle -A- clockwise and knurled
section -B- counterclockwise.
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