Subsequent Work

→ When replacing, note the following: → 453055 REPLACING HYDRAULIC UNIT/CONTROL UNIT .

Information 

• When fitting the hydraulic connections, the electric plug connections on the control units must remain connected as long as possible. This prevents the plug connections on the hydraulic unit or in the connectors inside from being splashed with brake fluid or water. 
• Any damp connector must be wiped dry before being disconnected from the connector on the hydraulic unit. If necessary, provide the connector with a suitable protector. 
• Brake fluid on electrical contacts (even thinned brake fluid) leads to corrosion and may cause faults in the system. 
• The brake lines must not be bent in the area of the hydraulic unit. 
• Clean the interfacing points of the brake lines, but not with cleaning agents. 
• Rinse off any brake fluid emerging thoroughly with water. 

1. Fill the brake lines by hand. To ensure the full function of the brake system, drain approx. 250 ccm brake fluid from each wheel → 470107 BLEEDING BRAKE SYSTEM
2. Bleed brake lines with the help of the PIWIS Tester II 9818  .

   To do this, select:

   > Control unit overview 

   > PSM 

   > Maintenance/repairs 

   > Bleed brakes 

   To finish, follow the menu guidance in PIWIS Tester II 9818  .

4. Carry out a swap test using PIWIS Tester II 9818  .

   To do this, select:

   > Control unit overview 

   > PSM 

   > Maintenance/repairs 

   > Hydraulic swap test 

   To finish, follow the menu guidance in PIWIS Tester II 9818  .

5. Perform a function test.
   1. 5.1. During the test drive, perform at least one ABS control operation, taking the road conditions into consideration.
   2. 5.2. On vehicles with PDK transmission, test the HOLD function if possible. If the combination sensor has been taught in incorrectly, the Hold function will not be active for inclines of more than 5%!
   3. 5.3. Read out the fault memory. There must not  be any stored faults.