ABS Hydraulic Unit , With Hydraulic Pump For Traction Control
ABS hydraulic unit -N55- with Hydraulic pump for traction control -V156-, removing and installing
Special tools and equipment
^ VAG1331 Torque wrench
^ VAG1869/2 Brake pedal loading device
The ABS hydraulic unit -N55- and the Hydraulic pump for traction control -V156- are located on left in engine compartment.
1 - Hydraulic unit with ABS return flow pump.
Hydraulic unit and ABS return flow pump are one unit and if malfunctioning must be replaced together.
2 - Electronic stabilization program hydraulic pump with brake pressure sender.
Electronic stabilization program hydraulic pump and brake pressure sender are one unit and if malfunctioning must be replaced together.
CAUTION! Do not bend the brake lines in the area of the hydraulic unit!
Removing:
^ Note or request radio code on vehicles with coded radio if necessary.
^ Disconnect battery.
^ Release connector from hydraulic unit (arrow -1-) and pull off (arrow -2-)
^ Install brake pedal depressor VAG 1869/2.
^ Depress brake pedal with brake pedal depressor.
^ Connect bleeder bottle hose to left-front brake caliper bleed screw and open bleed screw.
^ Close left-front bleeder screw.
^ Place lint-free cloths under the hydraulic unit.
Make sure no brake fluid gets onto contacts.
This work sequence is only valid for removal of the hydraulic unit.
^ Detach brake lines on the hydraulic unit.
^ Seal brake lines and threaded holes with plugs from repair set Part No. 1 HO 698 311 A.
^ Remove hex nuts on hydraulic unit bracket -arrows-.
^ Remove hydraulic unit.
This work sequence is only valid for removal of the ABS hydraulic unit -N55 and Hydraulic pump for traction control -V156-
^ Unscrew power steering reservoir -1- and place to side with hoses still connected.
^ Unscrew coolant expansion tank -2- and place to side with coolant hoses still connected.
Vehicles with electric vacuum pump
^ Remove electric vacuum pump, Refer to Vacuum Pump, Brakes, Service and Repair
Continued for all vehicles
^ Remove brake lines on the hydraulic unit and electronic stabilization program hydraulic pump.
^ Seal brake lines and threaded holes with plugs from repair set Part No. 1H0 698311 A.
^ Disconnect connector off electronic stabilization program hydraulic pump.
^ Removal brake fluid supply hose off electronic stabilization program hydraulic pump.
^ Remove securing bolts on hydraulic unit bracket.
^ Take hydraulic unit with electronic stabilization program hydraulic pump off upward.
Installing:
Note:
^ Remove sealing plugs on new hydraulic unit when the corresponding brake line is going to be installed.
^ Installation is carried out in the reverse sequence
The Hydraulic pump for traction control -V156must be activated first to bleed the brake system.
^ Perform activation of electronic stabilization program hydraulic pump in display group number 2 of "Introduce basic settings".
go to Perform basic setting in "Guided fault finding" using VAS 5051.
Note: Start "Guided fault finding" by pressing the "Go to" button in "Select function/component".
^ Bleeding brake system, Refer to Brake Bleeding, Service and Repair
^ Enter radio code.
^ Code control unit
go to Code control unit using VAS 5051 via "Guided fault finding" function.
Tightening torques:
Brake lines to ABS unit and electronic stabilization program hydraulic pump
Thread M10 x 1 14 Nm
Thread M 12 x 1 14 Nm
ABS hydraulic unit -N55- hex nut to retainer, Refer to ABS/EDL/ASR/ESP Bosch 5.3 from M.Y. 2000: hydraulic unit, brake servo/brake master cylinder, assembly overview; item 7
Hydraulic pump for traction control -V156- to bracket, Refer to ABS/EDL/ASR/ESP Bosch 5.3 from M.Y. 2000: hydraulic unit, brake servo/brake master cylinder, assembly overview; item 17
Bracket hex bolt to body, Refer to ABS/EDL/ASR/ESP Bosch 5.3 from M.Y. 2000: hydraulic unit, brake servo/brake master cylinder, assembly overview; item 13