B3FD3MK1 - 307
EMERGENCY BRAKING ASSISTANCE CHECK, SYSTEM EVA BOSCH
1 - DATA : BRAKE CONTROL EVA
P : Master cylinder pressure (in bars) .
F : Pedal force (in dan) .
1 : Slow braking range .
2 : (emergency) rapid braking curve .
The emergency servo ratio is triggered when the brake pedal speed exceeds a speed threshold (adjusted in production) .
2 - ANOMALY(IES) - CAUSES - REMEDIES
| anomaly(ies) | causes | remedies |
|---|---|---|
| the brake control is permanently over-assisted | master cylinder EVA : the fast gear remains engaged | check : master cylinder check EVA |
| no over-assistance during rapid braking | master cylinder EVA :valve faulty | check : master cylinder check EVA |
| pedal stiff | vacuum source faulty | check : VACUUM CIRCUIT |
| pedal travel long with no trace of an external leak | air in the circuit cup or valve faulty |
BLEED THE CIRCUIT REPLACE THE MASTER CYLINDER |
| significant drop in the brake fluid level with no trace of a leak | master cylinder : the brake fluid flows into the servo | REPLACE THE MASTER CYLINDER AND THE SERVO |
3 - CHECK : FIRST METHOD
The check allows triggering of the system to be checked (curve 1 and 2), but not the trigger speed threshold .
This procedure is based on analysis of the sensations detected from the system EVA .
Drive at a speed of 50 km/h in 3 gear .
Press the brake pedal slowly until a normal urban driving type brake force is reached .
Maintain this force at a constant level until the vehicle stops .
With the vehicle stationary, maintain this force at a constant level then memorise it .
Release the brake pedal .
Drive at a speed of 50 km/h in 3 gear .
Press the brake pedal very rapidly, but with the same force as previously .
Conclusion :
If incorrect : replace the master-cylinder .
If incorrect : replace the master-cylinder .
4 - CHECK : SECOND METHOD
The check allows triggering of the system to be checked (curve 1 and 2), but not the trigger speed threshold .
4 - 1 - SPECIAL TOOLS
[1] Braking pressure checking device (-).0808-ZY .
[2] Union for caliper bleed screw (-).0808-D .
Braking tester with approved pedometer PEUGEOT .
4 - 2 - SETTING UP THE TOOLS
Protect the wings and the seats .
Remove the left-hand front wheel .
Remove the front left side mud guard .
Route the larger of the two pipes (1) of the tool [1] from the engine compartment to the wheel arch .
BOSCH : M7 X 100 caliper .
Remove the left caliper bleed screw .
Fit the tool [2] .
Connect the pipe (1) to the union [2] .
Clamp the pipe (1) to the brake hose .
WARNING : the pipe (1) must not touch the rotating part .
Bleed the checking equipment .
Replace the front left side mud guard .
Fit the wheel .
Place the tool [1] in a plastic bag then place it next to the driver .
Install the pedometer .
Start the vehicle .
4 - 3 - CHECK
Carry out a complete manual front brake cycle .
Move the vehicle forward then start the rear brake checking cycle .
When conditioning appears on the screen, press the brake pedal gradually until a value of 5 da.n is displayed on the pedometer .
Note the value on the tool [1] : The pressure should be between 15 and 20 bars .
Release the brake pedal .
Wait for 30 seconds .
Press the brake pedal very rapidly to display a value of 5 da.n on the pedometer .
Note the value on the tool [1] : The pressure should be between 40 and 50 bars .
If incorrect : replace the master-cylinder .