Removing and installing hydraulic control unit and bracket — VW

Hydraulic control unit
The hydraulic pump -V64, the hydraulic unit -N55 and the control unit -J104 form the hydraulic control unit.
The hydraulic control unit must be removed and installed as one complete unit => Page
01-16
Servicing => Page
01-20

Brake line 15 Nm
Between brake master cylinder/pushrod piston circuit and hydraulic unit

Brake line 15 Nm
Between brake master cylinder/floating piston circuit and hydraulic unit

Brake line 15 Nm
To front right brake calliper

Brake line 15 Nm
To rear left brake calliper

Brake line 15 Nm
To rear right brake calliper

Brake line 15 Nm
To front left brake calliper

Multi pin connector/control unit
25-pin
Do not unplug connector before completing Self-diagnosis. Switch off ignition before disconnecting

Hexagon nut 20 Nm
Bracket
Fit bolt 8 Nm
Cap nut 20 Nm

Removing hydraulic control unit:

Observe or obtain radio code on vehicles with coded radio.
Disconnect battery.
Depress brake pedal and lock with brake pedal depressor from V.A.G 1238/B.

Pull plug -1- of air-mass meter off air duct pipe of air filter.
Unscrew bolts -2- at air filter -3- and set filter aside on left.

Place an absorbent towel under the hydraulic control unit to catch escaping brake fluid.

Note:

The brake lines around the hydraulic unit must not be bent.

Unscrew brake lines leading from brake master cylinder to hydraulic unit (see arrows) and use sealing caps from repair kit Part No. 1H0 698 311 A to keep out dirt.
On LHD vehicles, lift the disconnected brake lines clear and tie them in place with welding wire so that the ends of the pipes are higher than the brake fluid level in the expansion tank.
Detach remaining brake lines from hydraulic unit.

Seal connections of hydraulic lines at hydraulic unit with plugs -Pos. 2- and -item 3- from repair kit, part no. 1H0 698 311 A.

Note:

When working on the system, and when performing the following step in particular, it is important to ensure that no brake fluid enters the connector housing of the control unit. This can result in corrosion of the contacts and failure of the system . In case of contamination clean plug-in housing thoroughly with compressed air. For this purpose,the hydraulic line connectionsat the hydraulic unit must always be protected with the plugs from the repair set, part no. 1H0 698 311 A.

Release multi-pin connector and disconnect from control unit.

Remove bolts from bracket for hydraulic unit.
Remove hydraulic control unit.

Installing hydraulic control unit:

Notes:

Only remove sealing plugs on hydraulic unit when the relevant brake line is being fitted.
If the sealing plugs are removed too early, brake fluid can escape, and it may no longer be possible to fill and bleed the unit properly.

Install hydraulic control unit in reverse order.
Bleed brake system

=> Running gear; Repair group 47; Bleeding brake system and changing brake fluid
Running gear
Bleeding brake system and changing brake fluid

If a new control unit is fitted it must be coded =>Page
01-71
.