Volkswagen Workshop Service and Repair Manuals

Command unit for hydraulic unit - remove and install Special tools and workshop equipment required

t  "Torque wrench - 5 to 50 Nm (enc. 1/2")" -VAG 1331-

t  Brake pedal pressing device -VAG 1869/2-

Plug repair set 1H0 698 311 A After disconnecting the command device from the hydraulic unit, always place the valve tube transport protection in the hydraulic unit Hydraulic units without the transport protection are not covered by warranty. 1 -  Valve tube transport protection 2 -  Plugs M 10 3 -  Plugs M 12 Remove Installation location: The command unit is screwed to the hydraulic system unit and is found in the right side of the engine compartment.   WARNING The brake pipes in the hydraulic unit area must not be bent! –  Note the coding in vehicles with code radio equipment, request such coding if necessary. –  Disconnect the battery → Electrical system; Rep. Gr.27. 3 cylinders, injection engine: –  Disconnect the vacuum hoses from the upper air filter case section.

–  Remove the cover by the points marked with -arrows-. 4 cylinders, injection engine: –  Pull the hose from the oil separator and the check valve on the upper air filter case section.

–  Remove the cover by the points marked with -arrows-. 3-cylinder diesel engine: –  Pull the engine cover up and away from the fittings.

–  Remove the intake hose -1-. 4-cylinder diesel engine with injector pump unit: –  Pull the engine cover up and away from the fittings.

–  Remove hose -1- and intake tube -2- → Engine; Rep. Gr.23. or:

–  Remove the flexible aspiration tube-1- and Motor for intake manifold valve -V157--2- → Engine; Rep. Gr.23. 4 cylinders, diesel engine with distribution injector pump: –  Pull the engine cover up and away from the fittings.

–  Remove the escape gas return valve -1-. Continuation for all vehicles: –  Disengage Brake pressure sensor 1 -G201- connector -2-.

–  Unlock -arrow 1- and disengage -2- the ABS hydraulic unit -N55- connector. –  Place the Brake pedal pressing device -VAG 1869/2-. –  Press the brake pedal with the actuator. –  Place the venting hose of the venting reservoir over the left front brake caliper plug and open the plug. –  Close the left front venting plug. –  Put an adequate number of lint-free cloths under the command unit and the hydraulic unit. Make sure that no brake fluid reaches the contacts.

–  Loosen and hang the hydraulic unit brake pipes -1- to the brake cylinder. –  Release the remaining hydraulic unit brake pipes. –  Close the brake pipes and threaded holes with plugs from the repair set number 1H0 698 311 A. –  Unscrew the hexagonal nuts -5- from the command unit/hydraulic unit. –  Remove the hydraulic unit with the command unit. –  Unscrew the hexagonal nuts -2- and -4- and remove the command unit/hydraulic unit support. Install t  Only remove the plugs from the new hydraulic unit when the respective brake pipe is assembled. t  If the plugs were already removed from the hydraulic unit, the brake fluid may leak to the point that proper venting and filling can no longer be ensured. –  Installation is performed in the reverse sequence of the removal. –  Bleed the brake system → Chapter –  Code ABS control unit -J104-. Connect the Diagnosis, Measurement and Information System -VAS 5051A /52-and select the function → Chapter. –  Code the radio.

Tightening torques:
Command device to hydraulic unit t  Use new screws!	3 Nm
Brake pipes in the ABS set:
Threads M 10 x 1	14 Nm
Threads M 12 x 1	14 Nm
Hexagonal nut on the body	20 Nm
Hexagonal head screw to hydraulic unit on the support	8 Nm