Skoda Workshop Service and Repair Manuals

Removing and installing the hydraulic control unit - LHD version The removal and installation of the relevant hydraulic control unit is described according to the example of the ABS system BOSCH 5.7. Removal and installation is similar for the ABS/EDL/TCS or ABS/EDL/TCS/ESP BOSCH 5.7.   WARNING t  Make absolutely sure that no brake fluid gets into the plug connector housing of the hydraulic control unit. This may result in the corrosion of the contacts and to system failure. t  Carefully clean out the plug connector housing with compressed air if it gets dirty. t  Do not bend the brake lines around the hydraulic control unit. Special tools and workshop equipment required t  Brake pedal arrester, e.g. -V.A.G 1238 B- or brake pedal load -V.A.G 1869/2 - t  Vehicle system tester -V.A.G 1552- or vehicle diagnosis, measurement and information system -VAS 505x- t  Brake filling and bleeding device, e. g. -VAS 5234- t  Bleeding bottle (commercially available) t  Repair kit SP-No. 1H0 698 311 A t  Brake fluid → Chapter Removing:   Note Before disconnecting the battery determine the code of radio sets fitted with anti-theft coding. –  Disconnect battery → Electrical System; Rep. gr.27. –  Remove engine cover → Engine, Mechanics; Rep. gr.10. Vehicles with TDI PD Turbocharger engines

–  Remove top charge-air pipe -1- with connecting hose -2- → Engine, Mechanics; Rep. gr.21.

Continued for all vehicles –  Actuate brake pedal and arrest with brake pedal arrester. –  Attach the bleeder hose of the bleeding bottle onto the vent valve of the front left brake caliper and open bleeder valve. –  Shut the vent valve once the brake fluid has flown out. –  Disconnect the bleeder hose from the vent valve. –  Place sufficient non-fluffing cloths under and around the hydraulic control unit.

–  Unlatch the multi-pin connector -arrow 1- and pull off upwards from the control unit -arrow 2-. –  Close the plug connector housing of the control unit with a cap. –  If necessary remove the brake lines from the line holder. –  Mark brake lines. –  Unscrew brake lines from hydraulic control unit. –  Close off immediately brake lines. –  Shut off immediately threaded bores (brake line connections) on the hydraulic control unit with plugs from repair kit SP No. 1 H0 698 311 A. vehicles with ABS/EDL/TCS/ESP BOSCH 5.7   Note To avoid overvoltage and static discharge do not touch the plug contacts of the brake pressure sender 1 -G201-. –  Unplug connector from brake pressure sender 1 -G201-.

Continued for all vehicles –  Separate bracket -1- from the fixing bolt of the bracket -2-. –  Release the screws -arrows- and remove hydraulic control unit from bracket -2-. Installing:   Note t  New hydraulic control units are filled with brake fluid and pre-bled. t  Only then remove plugs from the hydraulic unit when the relevant brake line is installed. t  If the plugs were already removed from the hydraulic unit before the brake line is installed, then brake fluid may escape and adequate filling and bleeding can no longer be guaranteed.

–  Screw bracket -2- onto the hydraulic control unit. –  Tighten up the screws -arrows- fully to the specified tightening torque. –  Insert bracket -1- onto the fixing bolt of the bracket -2-.   Note Do not immediately tighten the nuts for securing the hydraulic control unit to the body. This facilitates the screwing of the individual brake lines onto the hydraulic control unit. –  Install the hydraulic control unit and screw on nuts as well as collar nut. vehicles with ABS/EDL/TCS/ESP BOSCH 5.7 –  Mount plug on brake pressure sender 1 -G201-. Continued for all vehicles –  Remove plugs from the brake lines to be installed.   WARNING Pay attention to the correct channel assignment of the brake lines. Interchanging the brake lines will result in dangerous brake control actions. –  Connect the brake line to the hydraulic control unit and tighten → Chapter. –  Tighten the collar nut and nuts for securing the hydraulic control unit to the specified tightening torque. –  Insert the multi-plug connector on the control unit and lock. Further installation occurs in reverse order.

Vehicles with TDI PD Turbocharger engines –  Install top charge-air pipe -1- with connecting hose -2- → Engine, Mechanics; Rep. gr.21. Continued for all vehicles –  Installing engine cover → Engine, Mechanics; Rep. gr.10. –  Connect battery → Electrical System; Rep. gr.27. –  Bleeding Brake System → Chapter. –  Code the control unit → Chapter. –  Perform null balance of the steering angle sender -G85- (only for vehicles with ABS/EDL/TCS/ESP BOSCH 5.7) → Chapter. –  Perform automatic test sequence → Chapter either using the vehicle system tester -V.A.G 1552- or the vehicle system test → Vehicle diagnostic, testing and information system VAS 5051 using the vehicle diagnosis, measurement and information system -VAS 505x- If faults are stored in the fault memory: –  Remove fault → Chapter. –  Erasing fault memory → Chapter.   Note For vehicles with ABS/EDL/TCS or ABS/EDL/TCS/ESP BOSCH 5.7 perform a test drive after bleeding with at least one ABS control!

Tightening torques:

Hydraulic control unit to bracket	8 Nm
Bracket to hydraulic control unit and to body t  Use new nuts and new hexagon collar nut!	20 Nm
Brake line to hydraulic control unit	14 Nm