Replacing The Wire Harness For Brake Booster
Replacing wire harness for brake booster
Tools
Technical values
Preliminary work
1. Disconnect battery.
2. Remove the carrier for the instrument panel.
3. Remove heater/air-conditioning unit.
4. Remove linings in engine compartment.
5. Remove wiper motor.
Removing wire harness for brake booster
1. Remove cover on cable duct (above the pedals) -arrow-.
INFORMATION: When cutting the wire harness for the brake booster, make sure there is enough length of cable left to join to the new lines.
2. Cut off wire harness for brake booster in area -a- (top right, next to the pedals).
3. Remove fabric tape and tie-wraps in area -b- and expose the remaining lines.
4. Screw off ground strap -1- on the centre firewall.
4.1. Screw off the fastening nut on the centre firewall and remove the ground strap with the twist lock - arrow A-.
4.2. Unclip wire harness at the retaining clip -arrow B-.
5. Pull off connector on brake fluid reservoir -4-.
5.1. Release connector on brake fluid reservoir -arrow A- and pull it off -arrow B-.
6. Pull off connector on brake booster -5-.
6.1. Release connector on brake booster using a suitable aid (e.g. angled piece of wire) -a- ( -arrow A- ) and pull it off -arrow B-.
7. Pull off way-sensor connector (brake assist) -6-.
7.1. Release way-sensor connector (brake assist) using a suitable aid (e.g. angled piece of wire) -a- ( -arrow A- ) and pull it off -arrow B-.
8. Pull off pressure sensor connector (brake assist) -7-.
8.1. Release pressure sensor connector (brake assist) using a suitable aid (e.g. angled piece of wire) -a- ( -arrow A- ) and pull it off -arrow B-.
9. Loosen wire harness on the centre firewall.
9.1. Open retaining clips -arrows A- and remove the line -arrow B-.
9.2. Open both holders (brake assist) -arrows C- and remove wire harness -arrow D-.
10. Remove rubber sleeve -8- on the centre firewall.
10.1. Unclip wire harness for brake booster from the centre firewall at the retaining clip -arrow A-.
10.2. Remove rubber sleeve on the centre firewall in direction of the engine compartment -arrow B- and remove wire harness for brake booster.
Installing wire harness for brake booster
1. Remove rubber sleeve -8- on the centre firewall.
1.1. Push wire harness for brake booster through from the engine compartment towards the interior - arrow A- and fit rubber sleeve on the centre firewall.
1.2. Clip in wire harness for brake booster on the centre firewall with the retaining clip -arrow B-.
2. Secure wire harness on the centre firewall.
2.1. Insert wire harness into the two holders -arrows A- and close the holders -arrows B-.
2.2. Insert line into the two retaining clips -arrows C- and close the retaining clips -arrows D-.
3. Plug in pressure sensor connector (brake assist) -7-.
3.1. Plug in connector on pressure sensor (brake assist) -arrow- until it engages securely.
4. Plug in connector on way-sensor (brake assist) -6-.
4.1. Plug in connector on way-sensor (brake assist) -arrow- until it engages securely.
5. Plug in connector on brake booster -5-.
5.1. Plug in connector on brake booster -arrow- until it engages securely.
6. Plug in connector on brake fluid reservoir -4-.
6.1. Plug in connector on brake fluid reservoir -arrow- until it engages securely.
7. Screw on ground strap -1- on centre firewall.
7.1. Clip in wire harness on the firewall with the retaining clip -arrow A-.
7.2. Connect ground strap together with the twist lock to the threaded bolt on the centre firewall -arrow B- and secure with the fastening nut. - Tightening torque: 9 Nm (6.5 ftlb.)
INFORMATION:
- Select a place for the joint where there is enough space to join all the lines present.
- Do not cut the lines too short in case they have to be laid in a different position if there is insufficient space in the area of the joint.
- The electric lines are located in the plenum panel and are thus exposed to the highest demands.
- The greatest care must be used in the individual work steps for stripping insulation from, crimping, and shrinking/insulating the electric lines.
- The procedure for stripping insulation from, crimping, and shrinking/insulating the electric lines must be complied with and observed. The procedures are described in detail in the Repair kit for Cayenne harnesses NR.155-2.
- Crimping samples are to be prepared before beginning work.
8. Crimp the lines in area -a- (in cable duct above the pedals).
8.1. Cut off lines in different lengths (due to the shrink-fit connections).
8.2. Slide shrink-fit hoses onto the lines.
8.3. Strip 10 mm of insulation off the lines.
8.4. Crimp the lines using crimping sleeves and the manual crimping pliers from the repair kit for Cayenne wire harnesses NR.155-2.
8.5. Slide the shrink-fit hoses over the crimp connections and carefully shrink them using the hot-air blower with special nozzle (recommended accessories for the repair kit for wire harnesses) so that they are watertight.
8.6. Wrap commercially available PVC tape all around the area of the connection points.
9. Secure the repaired area -b- to the main wire harness with tie-wraps.
10. Fit cover on cable duct (above the pedals) -arrow-.
Subsequent work
1. Install wiper motor.
2. Install linings in engine compartment.
3. Install heater/air-conditioning unit.
4. Install the carrier for the instrument panel.
5. Carry out work instructions after disconnecting the battery.