Peugeot 308: Draining - filling - bleeding : Braking circuit

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).

ESSENTIAL : All personnel working on vehicles with a fuel cell stack must have completed the STELLANTIS training courses required to work on these vehicles(observe the regulations in force in the respective country).

1. Tooling

Workshop equipment :

• A bleed unit approved by the manufacturer (Type SAM FET-20 / WE180011A )
• A diagnostic tool

2. Precautions / Recommendations

2.1. General

CAUTION : During the bleed operations, take care to maintain the level of brake fluid in the reservoir by topping it up.

CAUTION : Respect the order of opening of the bleed screws.

Bleeding order :

• The rear right-hand wheel
• The rear left-hand wheel
• The front right-hand wheel
• The front left-hand wheel

2.2. When replacing the brake fluid

Procedure to be followed :

• Draining / Filling of the tank
• Primary circuit bleed

2.3. When replacing the hydraulic block

Vehicles fitted with ABS/ESP have a system consisting of 2 braking circuits :

• The primary braking circuit which is the main circuit pressurised directly by the brake pedal
• The secondary braking circuit inside the hydraulic block

CAUTION : When replacing the hydraulic block, it is not necessary to bleed the secondary circuit of the hydraulic block.

CAUTION : The secondary circuit can only allow in air when the internal electrovalves are operating with a circuit full of air.

Procedure to be followed :

• Open 2 bleed screws that are on the same side of the vehicle
• Place a pedal clamp on the brake pedal in order to prevent the brake fluid from flowing out of the reservoir
• Replace the hydraulic block
• Bleed the primary braking circuit

2.4. When replacing a brake caliper or a wheel cylinder

Procedure to be followed :

• Open 2 bleed screws that are on the same side of the vehicle
• Place a pedal clamp on the brake pedal in order to prevent the brake fluid from flowing out of the reservoir
• Replace the brake caliper or wheel cylinder that is faulty
• Bleed the new brake caliper or wheel cylinder

2.5. When replacing a master-cylinder

Procedure to be followed :

• Drain the reservoir
• Replace the master-cylinder
• Slacken the master-cylinder hydraulic unions
• Fill until the brake fluid starts flowing out through the hydraulic unions
• Tighten the master-cylinder hydraulic unions
• Bleed the primary braking circuit

N.B. : If the master cylinder is removed-refitted, it is advisable to complete the automatic bleed with a manual bleed.

3. Draining / Filling of the tank

CAUTION : Use only new, foam-free brake fluid . Avoid any introduction of impurities into the hydraulic circuit.

CAUTION : Use only approved and recommended hydraulic fluid(s) : DOT4.

"A" remote assembly.

"B" direct assembly.

3.1. Draining

Remove :

• The brake fluid reservoir cap (1)(at "a")
• The filter of the brake fluid reservoir (1)(depending on equipment)

Drain the brake fluid reservoir ( 1) as much as possible ; Using a clean syringe.

3.2. Filling

Refit the brake fluid reservoir filter(depending on equipment).

Fill the brake fluid reservoir (1) to its maximum capacity(at "a").

Bleed the primary braking circuit.

4. Bleeding the primary braking circuit

ESSENTIAL : Bleed the primary circuit until clean, non-foaming brake fluid is obtained.

CAUTION : Respect the order of opening of the bleed screws.

Bleeding order :

• The rear right-hand wheel
• The rear left-hand wheel
• The front right-hand wheel
• The front left-hand wheel

CAUTION : Do not switch on the ignition at any time during the operation.

N.B. : There are 2 bleed procedures for the primary braking circuit.

4.1. Bleeding the primary braking circuit ; Using the bleeding apparatus (Action recommended )

CAUTION : Keep to the pressures recommended . Never exceed 5 bars.

presses :

• Vehicles manufactured prior to year 2005, pressure lower than 2 bars
• Vehicles manufactured after year 2005, pressure between 3 and 5 bars

Connect the bleeding apparatus on the brake fluid reservoir (1).

Bleed the circuit following the instructions for use of the equipment.

Progressively increase the pressure.

Visually check :

• Note down or print out the parameters so that you can re-write them in the new ECU
• The general condition of the braking circuit

4.2. Bleeding the primary braking circuit ; Without the bleeding device

ESSENTIAL : This operation must be performed with the vehicle on the ground.

CAUTION : Two operators are necessary.

N.B. : To make it easier to access the bleed screw on the front brake calipers, turn the wheels to full lock on the side of the brake caliper to be bled.

Fill the brake fluid reservoir (1) to its maximum capacity.

Connect a transparent pipe on the bleed screw of the brake caliper or wheel cylinder (Rear left ).

Press slowly on the brake pedal to put the braking circuit under pressure.

Keep the brake pedal pressed.

Open the bleed screw (The brake pedal should descend and the pressure should drop ).

Hold the pedal fully down.

Close the bleed screw .

Allow the brake pedal to return naturally.

Wait 2 seconds for the fluid to arrive in the master-cylinder.

Repeat the operation until the fluid running out is clean and free from air bubbles.

N.B. : Value indicative 10 to 20 times.

Repeat the operation on the rear RH brake caliper or wheel cylinder, and on the front RH and front LH brake calipers.

4.3. Check

At the end of the bleed programme, check and top up, if necessary, the brake fluid level.

Start the engine (To establish the vacuum in the brake servo ).

Check the travel and the feel of the brake pedal (Excessive travel, sponginess, lack of resistance ).

If the travel of the brake pedal is excessive :

• Check the braking circuit (No leaks )
• Check the clutch circuit (Correctly bled, no leaks )

If there are no leaks, repeat the procedure for bleeding the primary braking circuit.

Carry out a road test(if necessary).

5. Bleeding of the secondary braking circuit (Internal to the hydraulic block )

CAUTION : Bleeding of the secondary braking circuit is done with a diagnostic tool.

CAUTION : This procedure is only carried out if the primary braking circuit has been bled.

CAUTION : The bleed is carried out with the engine off and requires two operators (Ignition on ).

CAUTION : Keep to the pressures recommended . Never exceed 5 bars.

presses :

• Vehicles manufactured prior to year 2005, pressure lower than 2 bars
• Vehicles manufactured after year 2005, pressure between 3 and 5 bars

5.1. Bleeding

Connect the bleeding apparatus on the brake fluid reservoir (1).

Bleed the secondary braking circuit (Refer to the procedure in the diagnostic tool and also to the bleed apparatus user instructions ).

At the end of the bleed programme, check and top up, if necessary, the brake fluid level.

5.2. Check

At the end of the bleed programme, check and top up, if necessary, the brake fluid level.

Start the engine (To establish the vacuum in the brake servo ).

Check the travel and the feel of the brake pedal (Excessive travel, sponginess, lack of resistance ).

If the travel of the brake pedal is excessive :

• Check the braking circuit (No leaks )
• Check the clutch circuit (Correctly bled, no leaks )

If there are no leaks, repeat the procedure for bleeding the primary braking circuit.

Carry out a road test(if necessary).

6. Topping up

N.B. : During the filling operation, the cap (2) must be placed in readiness nearby in a flat, clean area.

Remove the cap (2).

Fill the tank (1) to the maximum(at "b").

Refit the cap (2).