Removing and installing ABS control unit J104 and ABS hydraulic unit N55, up to week 27/2012 — VW

Removing and installing
ABS control unit
J104
and
ABS hydraulic unit
N55
, up to week 27/2012
Special tools and workshop equipment required
Torque wrench
V.A.G 1331
Open ring spanner insert, AF 11 mm
V.A.G 1410/6
Universal joint
V.A.G 1410/7
Torque wrench
VAS 6854
Brake pedal depressor
V.A.G 1869/2
Assembly tool
V.A.G 1410/8
Sealing plugs from repair kit, part number 1 H0 698 311 A
2
Sealing plug M10
3
Sealing plug M12
Removing
Location:
The
ABS control unit
J104
is bolted to the
ABS hydraulic unit
N55
and is located on the left in the engine compartment.
If problems are reported, the hydraulic unit and the control unit must be renewed together.
WARNING
Do not bend the brake lines in the area of the hydraulic unit!
Note or request radio code on vehicles with coded radio if necessary.
Disconnect battery
Electrical system
Rep. gr.
27
Battery; Disconnecting and reconnecting battery.
Connect bleeder bottle hose to front left brake caliper bleed valve and open bleed valve.
Use
brake pedal depressor
V.A.G 1869/2
to depress brake pedal.
Close front left bleed valve.
Place sufficient lint-free cloths under the control unit and hydraulic unit.
Note
Ensure no brake fluid gets onto contacts.
Unscrew brake lines
1
to
4
,
A
and
B
from
ABS hydraulic unit
N55
.
Seal brake lines and threaded holes using
sealing plugs
1H0 698 311 A
from repair kit.
Release retainer
1
for connector
2
on control unit in direction of
arrow A
and pull connector from control unit in direction of
arrow B
.
Remove
ABS hydraulic unit
N55
together with
ABS control unit
J104
1
.
To do this, first pull
ABS hydraulic unit
N55
with
ABS control unit
J104
out of rubber buffers
4
beneath control unit and then beneath hydraulic unit.
Remove bolt
3
from retaining plate
2
.
Installing
Note
If the
ABS hydraulic unit
N55
with the
ABS control unit
J104
is renewed, it must be recoded in guided fault finding
Vehicle diagnostic tester
.
Install in reverse order. Note the following points:
Remove sealing plugs from new hydraulic unit only when the corresponding brake line is to be installed.
If sealing plugs are removed too early from the hydraulic unit, brake fluid can escape, and it can then no longer be guaranteed that the unit can be sufficiently filled and bled.
Caution
Brake line nuts must be screwed to end of threads into
ABS hydraulic unit
N55
by hand.
Only then may the nuts be tightened to the specified torque.
Bleed brake system
Chapter
.
Carry out a road test.
Perform road test at more than 40 km/h for at least 80 seconds.
Read event memory after road test
Vehicle diagnostic tester
.
Specified torques
Chapter
“
Assembly overview - control unit and hydraulic unit
”