Carrying Out Bleeding Operation - AR42.10-S-0010-02E

Model 447, 448

Risk of poisoning from swallowing brake fluid. Risk of injury from skin and eye contact with brake fluid

Only pour brake fluid into suitable and appropriately marked containers. Wear protective clothing and eye protection when handling brake fluid.

AS42.50-Z-0001-01A

FRONT AXLE FLOATING CALIPER

Number	Designation		Model 447, 448
BA42.10-Z-1001-03KOB	Bleed valve at front axle floating brake caliper	Nm	14

REAR AXLE BRAKE CALIPER

Number	Designation		Model 447, 448
BA42.10-Z-1001-12KOJ	Vent valve on rear axle floating brake caliper	Nm	14

The bleed pressure at the connected filling unit must be 2.0 bar.

Remove caps from bleed valves on all brake calipers (1, 2, 3, 4).
Mount bleed hose of bleed bottle onto bleed valve of right rear brake caliper (1).
Open bleed valve of brake caliper (1).

Courtesy of MERCEDES-BENZ USA
1. To bleed the hydraulic system of the brake system if the hydraulic system was opened for repair purposes.
  Repeatedly operate brake pedal until new brake fluid flows out without any bubbles.
  
  To bleeding the brake system correctly it is absolutely essential to pump the brake pedal throughout the entire bleeding process.
  
  Otherwise, brake system malfunctions and a failure of the brake system may occur due to remaining residual air.
  
  To prevent air from being drawn in, do not pump the brake pedal in a jerking manner but instead release it slowly.
  
  Otherwise, an extension or a repetition of the bleed procedure may be necessary.
  
  The bleed valve of the brake caliper (1) may remain open throughout the entire pumping procedure.
  
  Required total quantity of brake fluid: approx. 1.5 l.
2. To replace the brake fluid if the brake system's hydraulic system was not opened beforehand for repair purposes.
  Leave bleed valve of brake caliper (1) open, until new brake fluid flows out.
  
  Pumping of the brake pedal is not necessary. Required total quantity of brake fluid: approx. 0.75 l.
Close bleed valve of brake caliper (1).
Brake caliper (2, 4)

Brake caliper (1, 3)
Detach bleed hose of bleed bottle from bleed valve of brake caliper (1).
Repeat operation steps 2 to 6 on the remaining brake calipers (2, 3, 4).
Process brake calipers (2, 3, 4) in numerical sequence.
Fit caps for bleed valves onto all brake calipers (1, 2, 3, 4).