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 the wheel. Use assembly aids (assembly pins) -1-.
-> 44051900 Removing and installing wheel.
Brake disc and caliper (shown as an example)
Removing
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.
Overview of front brake caliper (shown as an example)
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 brake disc with caliper and assembly aids 1 (threaded bolts for fitting wheel), shown as an example
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 for brake pad wear indicator (shown as an example)
4. Disconnect plug connection for speed sensor.
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.
5. Set the brake pads back slightly and evenly using water pump pliers.
Information
Do not bend the brake lines.
- Detach brake line holders at the wheel carrier.
- For easier access to the holders, turn in the wheel carrier as required.
6. Remove the holders -1, 2- for the hydraulic lines on the wheel bearing housing -3-.
Mounting for hydraulic lines (shown as an example)
7. Loosen the brake line at the brake caliper. Collect the brake fluid in a suitable container. Close off the openings of the brake line and brake caliper using suitable stoppers.
Information
- Never use an impact bolter to loosen and tighten the brake caliper on the wheel carrier.
8. Carefully remove the brake caliper from the wheel carrier.
Fastening screws on brake caliper (shown as an example)
9. If new brake pads are fitted, read the information under "Removing and installing brake pads" -> 463619 Removing and installing front brake pads 463619 Removing and installing front disc brake pads
Installing
Installing front brake caliper
WARNING
Old mounting parts fitted on the brake caliper
- Reduced braking effect
- Risk of damage to the brake caliper
-> Fit new fastening screws
The brake caliper is installed in reverse order.
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.
The assembly pins T10439 => Brake caliper tool can be used to make it easier to install the brake caliper.
Brake caliper tool
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 holders -1, 2- for the hydraulic lines on the wheel bearing housing -3-.
Mounting for hydraulic lines (shown as an example)
4. Fit plug connection for speed sensor.
5. Fit the brake pad wear indicator.
Subsequent work
1. Bleed the brake system.
-> 470107 Bleeding brake system - section on "Bleeding" Service and Repair
2. Position disc brake pads by operating the brake several times.
3. If new brake pads are fitted, read the information under "Removing and installing brake pads" -> 463619 Removing and installing front brake pads 463619 Removing and installing front disc brake pads
4. Fit the wheel. Use assembly aids (assembly pins) -1-.
-> 44051900 Removing and installing wheel
Brake disc and caliper (shown as an example)
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!