B3FD3NK1 - 307

CHECK VACUUM CIRCUIT

1 - SPECIAL TOOLS

[1] Kit DIAL 2000 :

• [1a] unit DIAL 2000 (reference 1A)
• [1b] DIAL 2000 supply lead (reference 1B)

[2] Kit DEBI 2000 :

• [2a] flow/pressure sensor (reference 2A)
• [2b] 2 valve union (reference 2N)

2 - REMOVAL

Remove :

• the battery cover
• the battery
• the battery container

3 - CONNECTIONS

Disconnect the servo pipe (1) from the non-return valve (2) .

Position :

• the 2 valves connector [2b] between the non-return valve (2) and the power steering pipe outlet
• the tool [2a]
• the tools [1a] - [1b]

4 - PRELIMINARY OPERATIONS

Check :

• the condition of the pipes and unions
• tightening of the clips

WARNING : in order to isolate the power steering circuit, pinch the pipes connected to the attached equipment (solenoid valves) .

Comments : The values indicated are relative pressures .

The check must be carried out with the engine warm .

Stop the engine .

Ensure that the 2 valves of the union [2b] are open .

Press the brake pedal approximately ten times to establish the atmospheric pressure in the servo .

Select the menu : Brake servo on the tool [1a] ; Confirm (See instructions for use) .

5 - CHECK OF THE SEALING OF THE SERVO

Engine at idle : Wait until the pressure stabilises .

Simultaneously :

• close the valve (A)
• set the time base of the tool [1a] to zero

IMPERATIVE : do not press the brake pedal .

Stop the engine .

Checking value :

• variation in pressure : less than or equal to 0,03 bar(s) in 15 seconds

If the value is correct :

• diesel engine(s) : check ; the vacuum pump
• petrol engines : replace the pipe (1)

If the value is incorrect :

• check : the presence of the seal (3)
• check : tightening of the master cylinder on the servo : tightening torque : 2 da.Nm
• replace the non-return valve (2)

Carry out the check again .

If the value is incorrect :

• replace the brake servo unit

6 - VACUUM PUMP PRESSURE CHECK

Open the valves (A), (B) .

Press the brake pedal approximately ten times to establish the atmospheric pressure in the servo .

Close the valve (A) .

Set the time base of the tool [1a] to zero .

Start the engine ; Idling speed .

Open the valves (A) .

Checking value :

• - 1 ≤pressure (bars) ≤ - 0.8 in less than 30 seconds

If the value is incorrect :

• replace the pipe (1)

Carry out the check again .

If the value is incorrect :

• replace the vacuum pump

Rectify the circuit .

NOTE : if the control values are correct and the vehicle continues to exhibit symptoms of malfunction, check the sealing of the attached equipment connected to the vacuum circuit (use a NAUDER T 7050 type manual pump) .