Page 176 of 369

Downloaded from www.Manualslib.com manuals search engine 45-7
Safety precautions
WARNING!
Brake fluid is poisonous.
CAUTION!
Before working on the ABS or ABS/EDL
system, disconnect the battery Ground
(GND) strap. For anti-theft coded radios, first
make sure that the radio code is available.
Brake fluid must not contact painted parts. Brake fluid absorbs moisture from the air
and must therefore be replaced every two
years. Use only new, approved brake fluid
that complies with MVSS 116 DOT 4.
DO NOT use silicone-brake fluid (DOT 5).
Even the smallest traces can cause sever
corrosion in the brake system.
Before doing any welding repairs on the
vehicle using electric welding equipment,
disconnect the ABS control module.
After work that requires opening the brake
hydraulic system, bleed the system Page 47-29 . Page 2 of 3Anti-lock Brake System (ABS) and ABS with Electronic Differential Lock (ABS/EDL), Teves 20 GI12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.2
Page 177 of 369

Downloaded from www.Manualslib.com manuals search engine 45-8
CAUTION!
During the final road test, make sure that at
least one controlled brake test is included
(pulsations must be felt at the brake pedal).
Absolute cleanliness is required when
working on the ABS or ABS/EDL system. DO
NOT use any products that contain mineral
oil, such as oils, greases, etc.
Thoroughly clean all connections and the
immediate vicinity before loosening. DO NOT
use aggressive cleaning agents such as
brake cleaner, gasoline or thinners.
Place removed parts on a clean surface and
cover. DO NOT use fluffy cloths.
Carefully seal or cover opened components
if a repair cannot be completed immediately.
After separating the ABS hydraulic unit and
ABS control module, always use the plastic
foam transportation protection for the valve
dome, and always use the sealing plug kit
Part No. 1 H0 693 311 A.
Only install replacement parts that were
packed in their original packaging. Only
remove them immediately before installation. When the hydraulic system is open DO NOT
work with compressed air in the vicinity and
DO NOT move the vehicle.
Take precautions to make sure that brake
fluid does not enter any wiring harness
connectors. Page 3 of 3Anti-lock Brake System (ABS) and ABS with Electronic Differential Lock (ABS/EDL), Teves 20 GI12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.2
Page 178 of 369
Downloaded from www.Manualslib.com manuals search engine 45-9
ABS, ABS/EDL
hydraulic unit,
vacuum brake
booster and brake
master cylinder
(Teves 20 GI),
servicing
CAUTION!
DO NOT separate the ABS
hydraulic pump from the
valve block.
1 - Brake servo (vacuum
brake booster)
2 - Brake master cylinder
3 - Brake fluid reservoir
4 - Cap
5 - Self-locking nut Always replace 25 Nm (18 ft lb) 6 - Torx socket-head
bolt T25 4 Nm (35 in lb) 7 - Torx socket-head
bolt T25 8 Nm (71 in lb) Page 1 of 9ABS, ABS/EDL hydraulic unit, vacuum brake booster and brake master cylinder (Teves 20 GI), servicing12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.3
Page 179 of 369
Downloaded from www.Manualslib.com manuals search engine 45-10
8 - Rubber damper
9 - Retainer
10 - ABS hydraulic unit
11 - ABS control module
12 - Brake line connection ABS hydraulic unit to
right-front brake
caliper
13 - Brake line connection ABS hydraulic unit to
left-rear brake caliper
or wheel cylinder
14 - Brake line connection ABS hydraulic unit to
right-rear brake caliper or wheel cylinder
15 - Brake line connection ABS hydraulic unit to
left-front brake caliper
16 - Brake line Brake master cylinder
(secondary piston
circuit) to ABS
hydraulic unit
17 - Brake line Brake master cylinder
(primary piston circuit)
to ABS hydraulic unit Page 2 of 9ABS, ABS/EDL hydraulic unit, vacuum brake booster and brake master cylinder (Teves 20 GI), servicing12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.3
Page 180 of 369

Downloaded from www.Manualslib.com manuals search engine 45-11
ABS hydraulic unit and ABS control
module (Teves 20 GI), removing and
installing
Carefully read and follow all cautions and
warnings Page 45-7 before beginning work.
Location
The ABS control module is bolted to the ABS
hydraulic unit, located on the left-side of the
engine compartment.
CAUTION!
Do not bend brake lines at or near the ABS
hydraulic unit.
Switch ignition OFF when disconnecting and
reconnecting the ABS control module
connector.
Part numbers are listed here for reference
only. Always check with your Parts
department for the latest information. Sealing plug kit Part No. 1H0 698 311 A:
1 - Valve dome transportation protection (plastic
foam)
2 - Sealing plugs -M10- 3 - Sealing plugs -M12- Page 3 of 9ABS, ABS/EDL hydraulic unit, vacuum brake booster and brake master cylinder (Teves 20 GI), servicing12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.3
Page 181 of 369
Downloaded from www.Manualslib.com manuals search engine 45-12
After separating ABS control module from ABS
hydraulic unit, always install valve dome
transportation protection on hydraulic unit.
Warranty claims for ABS hydraulic units on which
the valve dome transportation protection was not
used will not be accepted.
Removing
CAUTION!
Determine correct radio anti-theft coding
before disconnecting the battery.
- Disconnect battery Ground (GND) strap.
- Remove coolant expansion tank and swing to
one side. Page 4 of 9ABS, ABS/EDL hydraulic unit, vacuum brake booster and brake master cylinder (Teves 20 GI), servicing12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.3
Page 182 of 369
Downloaded from www.Manualslib.com manuals search engine 45-13
- Release retainer and disconnect ABS control
module connector (arrows).
- Connect bleeder hose and bleeder bottle to left-
front brake caliper bleeder screw, and open
bleeder screw.
- Depress brake pedal at least 60 mm (2-3/8 in.). - Install brake pedal loading device from special tool
VAG 1238B.
- Close left-front bleeder screw. - Remove heat shield from brake master cylinder. - Disconnect brake lines from brake master cylinder
and ABS hydraulic unit.
- Seal lines and threaded holes with plugs from
repair kit Page 45-11 . Page 5 of 9ABS, ABS/EDL hydraulic unit, vacuum brake booster and brake master cylinder (Teves 20 GI), servicing12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.3
Page 183 of 369
Downloaded from www.Manualslib.com manuals search engine 45-14
-
Remove Torx socket-head bolts (T25) from
ABS hydraulic unit bracket.
- Remove ABS hydraulic unit/ABS control module
assembly.
- Disconnect ABS hydraulic pump connector from
ABS control module. CAUTION! - Remove ABS control module mounting bolts
(arrows) and pull off ABS control module. Pull control module straight off. Do not tilt. Cover control unit magnetic coils with a lint-
free cloth. After separating the ABS hydraulic unit and
ABS control module, always use the plastic
foam valve dome transportation protection
Page 45-11 . Page 6 of 9ABS, ABS/EDL hydraulic unit, vacuum brake booster and brake master cylinder (Teves 20 GI), servicing12/7/2004http://ebahn.bentleypublishers.com/vw/servlet/Display?action=Goto&type=repair&id=VW.B4.SU01.45.3