473919 Removing and installing front brake calliper (PCCB)
WM 473919 Removing and installing front brake caliper (PCCB)
Tools
Information
Note on pictures shown
Information
- The pictures shown in this document may differ from the original.
- However, this does not affect the validity and relevance of the pictures.
Preliminary work
Lift the vehicle.
-> 4X00IN Lifting the vehicle Service and Repair
Remove wheel. Use assembly aids (assembly pins) -1-.
-> 44051900 Removing and installing wheel.
PCCB brake disc and caliper
Removing front brake caliper
NOTICE
Removing/fitting wheels
- Risk of damage to (ceramic) brake discs
-> Use two assembly pins when removing and fitting the wheel.
-> Carefully guide the wheel towards the wheel hub, thereby preventing any heavy impact on the (ceramic) brake disc.
Information
- Do not open the brake system.
- Do not loosen the brake hose from the brake caliper when loosening the brake caliper.
- The core of the warning contact wire must not be left exposed! It does not matter if the insulation is worn.
- If necessary, remove a little brake fluid from the reservoir by suction in order to prevent an overflow when the disc brake pads are pushed back.
Overview of front brake caliper
1. Screw the two assembly aids (assembly pins) -1- , instead of two wheel bolts, into the wheel hub before removing/fitting the wheel. During removal, first remove the three remaining wheel bolts and remove the wheel carefully without touching the brake discs.
Front-axle PCCB brake disc with caliper and assembly aids 1 (threaded bolts for fitting wheel)
2. Then (after removing the wheel), remove the two assembly aids (assembly pins) -1- again.
Information
- To gain better access for removal of the brake caliper, turn the steering fully either to the right or left.
3. Release and unclip the connector for the brake pad wear indicator -1 and 2-.
Connector, brake pad wear indicator
NOTICE
Removal of brake caliper
- Paint defects on brake caliper
-> Proceed with care when setting back the brake pads.
-> Protect brake caliper from paint defects using a suitable cloth.
4. Evenly set back brake pads a little using water pump pliers.
5. Detach the retaining clip -arrow- for the cable of the brake pad wear indicator from the brake line.
Brake line holder
6. Disconnect the brake line -arrow- on the brake caliper and collect the brake fluid in a suitable container.
Brake line on brake caliper
7. Close off the brake line with a suitable plug.
Information
- Never use an impact bolter to loosen and tighten the brake caliper on the wheel carrier.
8. Remove brake caliper from wheel carrier -Bewegungspfeile-.
Brake caliper fastening screws
Installing front brake caliper
The brake caliper is installed in reverse order.
WARNING
Old mounting parts fitted on the brake caliper
- Reduced braking effect
- Risk of damage to the brake caliper
-> Fit new pad retaining springs
Information
- Never use an impact bolter to loosen and tighten the brake caliper on the wheel carrier.
- Visually inspect the thread for the brake caliper and blow it out carefully if necessary using compressed air. Use goggles!
- Replace screws.
- Observe correct tightening torques -> 4X00IN Tightening torques for the brake hydraulic system [1][2]Hydraulic System, Brakes.
Check that all parts are in perfect condition (visual inspection) and replace them if necessary.
To facilitate installation of the brake caliper, assembly pins T10439 => Assembly pin for brake caliper.
Assembly pin for brake caliper
1. Fit the brake caliper.
1.1. Carefully fit the brake caliper and screw in assembly pin in the top thread only by hand. The figure shows both assembly pins fitted, unlike the description! Not necessary here!
Assembly pins for brake caliper fitted (shown as an example)
1.2. Screw in bottom brake caliper screws several turns by hand (this protects the thread!).
1.3. Remove assembly pin and screw in top brake caliper screw several turns by hand (this protects the thread!).
1.4. Screw in both brake caliper screws fully and tighten to the specified tightening torque.
Information
Do not bend the brake lines.
- Secure brake line holders at the wheel carrier.
- For easier access to the holders, turn in the wheel carrier as required.
2. Fit the brake line to the brake caliper.
3. Fit the retaining clip for the cable of the brake pad wear indicator to the brake line.
4. Clip in the connector for the brake pad wear indicator.
5. Position disc brake pads by operating the brake several times.
Subsequent work
1. Bleed the brake system.
-> 470107 Bleeding brake system - section on "Bleeding" Service and Repair
2. Fit the wheel. Use assembly aids (assembly pins) -1-.
-> 44051900 Removing and installing wheel
PCCB brake disc and caliper
Bedding in the brake pads
New brake pads require a bedding-in period of approx. 200 km (124 miles)! Only then do they achieve their best friction and wear coefficient! During this period, the brakes should only be subjected to full stress at high speed in emergencies!