Peugeot 308: Check : Brake servo unit

ESSENTIAL : Observe the safety and cleanliness recommendations .

ESSENTIAL : All personnel carrying out work on a vehicle fitted with traction batteries must have received specific electric vehicle training and be authorised to work on these vehicles (observe the regulations in force in the respective country).

1. Tooling

1.1. Tooling

Tool	Reference	Description
	[0820]	"a" : Click-on connector
		"b" : Click-on connector

1.2. Workshop equipment

Manual pressure/vacuum pump type "SAM PPD3".

2. Checking for leaks (air)

CAUTION : Perform the operations that are required prior to a disconnection of the ancillaries battery .

CAUTION : In the case of a vehicle with 2 batteries, carry out the specific operations for disconnecting and reconnecting the ancillaries batteries.

Disconnect the ancillaries battery or batteries (depending on equipment).

Remove the ancillaries battery and its support.

Uncouple :

• Relative braking vacuum sensor (1) (at "b")
• The vacuum pipe (2) (at "a")

Couple up :

• The union "a" of the tool [0820] on the braking circuit vacuum sensor (3)
• The "SAM PPD3" type manual pressure/vacuum pump on the connector "b" of the tool [0820]

Operate the "SAM PPD3" type manual pressure/vacuum pump for vacuum until a value between -500 mbars and -850 mbars is obtained.

N.B. : The time taken to obtain the value varies according to the volume of air in the brake servo.

Wait for 1 minute.

Check the value .

Replace the brake servo ; Depending on the result of the check.

operation	Check / Result	Replacement of the brake servo
Vacuum creation	Value obtained	No ; Wait one minuteThen measure again
	Value cannot be obtained or at 0 mbar	Yes
Check (After one minute)	Identical value (± 10 Mbar)	No
	Variation of the value more than 10 mbars	Yes

3. Check : Presence of brake fluid

N.B. : A faulty master cylinder seal results in a leak of brake fluid in the brake servo.

N.B. : The brake fluid destroys the internal membrane of the brake servo.

Remove the master cylinder .

CAUTION : The choice of the object is very important, do not choose an object which has lint which degrades in the presence of brake fluid, a sharp object or any object which could damage the internal membrane of the brake servo.

Check for the presence of brake fluid at the lower part of the brake servo, by inserting a flexible object into the opening "c" (Example : Plastic tie wrap ) .

N.B. : If brake fluid is present, replace the master cylinder and brake servo assembly.