453019 Removing and installing hydraulic unit
WM 453019 Removing and installing hydraulic unit
Tools
Technical values
Preliminary work
1. Remove rear part of right front wheel housing liner-> 505619 Removing and installing front wheel housing liner - section on "Removing" Removal and Replacement.
2. Open the front lid.
Removing hydraulic unit
Information
Switch off the ignition for all replacement work on the hydraulic unit.
Overview
NOTICE
Replacing the hydraulic unit/control unit
- The hydraulic unit forms a single unit with the control unit.
- The hydraulic unit and control unit are always replaced together.
- When replacing the hydraulic unit/control unit, the new assembly must be to hand before the old one is removed.
- The data as well as the coding of the old control unit must be transferred to the new unit before the old one is removed.
-> When replacing, note the following: -> 453055 Replacing hydraulic unit/control unit 453055 Replacing hydraulic unit/control unit.
1. Disconnect brake lines -2- ().
Information
The electric plug connection and the third fastening screw for the hydraulic unit are accessible from the wheel housing.
.
Disconnecting brake lines
1.1. Mark three of the brake lines -2- to prevent them from being confused.
1.2. Unscrew cap screws -1- for the brake lines.
1.3. Pull brake lines -2- out of the bores and close off immediately with suitable plugs.
1.4. Lay brake lines aside carefully, fixing them in place if necessary.
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.
2. Detach supply lines -1- ().
Detaching supply lines
2.1. Mark one of the three supply lines -1- to prevent them from being confused.
2.2. Place a suitable cloth underneath to catch any emerging brake fluid.
2.3. Unscrew cap screws -2-.
2.4. Pull supply lines -1- out of the bores and close off immediately with suitable plugs.
2.5. Lay supply lines aside carefully, fixing them in place if necessary.
3. Unscrew fastening screws -3-.
4. Detach front part of right wheel housing liner and bend slightly to the side until the lower fastening screw -3- of the hydraulic unit can be accessed.
5. Disconnect electric push-on connector (accessible from the wheel housing).
Pulling off connectors
5.1. Press clip -1- downwards.
5.2. Push lever -2- upwards.
5.3. Remove electric connector.
6. Unscrew fastening screw -3-.
7. Remove hydraulic unit through engine compartment.
Installing hydraulic unit
NOTICE
Replacing the hydraulic unit/control unit
- The hydraulic unit forms a single unit with the control unit.
- The hydraulic unit and control unit are always replaced together.
- When replacing the hydraulic unit/control unit, the new assembly must be to hand before the old one is removed.
- The data as well as the coding of the old control unit must be transferred to the new unit before the old one is removed.
-> When replacing, note the following: -> 453055 Replacing hydraulic unit/control unit 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. The hydraulic unit is installed in reverse order to removal.
2. Secure front part of right wheel housing liner -> 505619 Removing and installing front wheel housing liner - section on "Installing" Removal and Replacement.
Observe tightening torques for fastening screws:
Hydraulic unit to support => Tightening torque: 10 Nm (7.5 ftlb.)+/-1 Nm (+/-0.5 ftlb.)
Hydraulic unit support to body => Tightening torque: 10 Nm (7.5 ftlb.)+/-1 Nm (+/-0.5 ftlb.)
Subsequent work
NOTICE
Replacing the hydraulic unit/control unit
- The hydraulic unit forms a single unit with the control unit.
- The hydraulic unit and control unit are always replaced together.
- When replacing the hydraulic unit/control unit, the new assembly must be to hand before the old one is removed.
- The data as well as the coding of the old control unit must be transferred to the new unit before the old one is removed.
-> When replacing, note the following: -> 453055 Replacing hydraulic unit/control unit 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 at each wheel-> 470107 Bleeding the brake system Service and Repair
2. Bleed brake lines with the help of the PIWIS Tester II 9818.
To do this, go to the menu:
> Control unit overview
> PSM
> Maintenance/repair
> Bleeding brakes
To finish, follow the menu guidance in the PIWIS Tester II 9818.
3.
4. Carry out a swap test with the help of the PIWIS Tester II 9818.
To do this, go to the menu:
> Control unit overview
> PSM
> Maintenance/repair
> Swap test of hydraulics
To finish, follow the menu guidance in the PIWIS Tester II 9818.
Information
If the hydraulic unit is replaced, the PSM control unit must be calibrated using the Porsche System Tester (calibration of hydraulic unit/control unit with combination sensor). Without calibrating, the PSM will have incorrect values or no values.-> 453055 Replacing hydraulic unit/control unit 453055 Replacing hydraulic unit/control unit
Always comply with the basic conditions for the function test.
- Vehicle is parked horizontally.
- Driver belted in.
- Vehicle doors and lids closed.
- Electric parking brake fully functional.
5. Perform a function test.
5.1. During the test drive, perform at least one ABS control operation, taking the road conditions into consideration.
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%!
5.3. Read out the fault memory. There must not be any stored faults.