Checking fluid levels
Check these levels regularly and top up if necessary, unless otherwise stated.
If a level drops significantly, have the corresponding circuit checked by the CITROËN network.
Oil level

This check is only valid if the vehicle is on level ground and the engine has been stopped for more than 15 minutes.
It is carried out either when the ignition is switched on, using the oil level indicator in the instrument panel, or using the dipstick.
Also check this level between each periodic maintenance service and before each long journey.
When working under the bonnet, take care as some engine areas may be extremely hot (risk of burns).
Dipstick

2 level marks on the dipstick:
- A = maximum; never exceed this level,
- B = minimum; top up through the oil filler cap, using the oil type suited to your engine.
Engine oil change
Refer to the service booklet for the frequency of this operation.
! To preserve engine reliability and emissions control systems, do not use additives in the engine oil.
Oil specifications
The oil must match your engine and comply with the manufacturer's recommendations.
Brake fluid level
The level of this fluid should be close to the "MAX" mark. Otherwise, check the brake pads for wear.
Draining the circuit
Refer to the service booklet for the frequency of this operation.
This fluid must be changed periodically.
An overly aged fluid can lead to a loss of efficiency.
Fluid specifications
This fluid must comply with the manufacturer's recommendations and meet the DOT4 standard.
Power steering fluid or power steering and suspension fluid level
To top up, contact a CITROËN dealer.
Coolant level
The level of this fluid must be close to the "MAXI" mark, never above it.
When the engine is hot, the temperature of this fluid is regulated by the cooling fan. The fan may run with the ignition switched off.
On vehicles fitted with a particulate filter, the cooling fan may run after the vehicle has been switched off, even when the engine is cold.
In addition, the cooling system is under pressure, so wait at least one hour after switching off the engine before carrying out any work.
To avoid any risk of burns, unscrew the cap two turns to release the pressure.
Once the pressure has dropped, remove the cap and top up the level.
Draining the circuit
This fluid does not need to be replaced.
Fluid specifications
This fluid must meet the manufacturer's recommendations.
Windscreen and headlamp washer fluid level
On vehicles fitted with headlamp washers, the minimum level of this fluid is indicated by a warning tone and a message on the multifunction display.
Top up the level the next time the vehicle is stopped.
Fluid specifications
To ensure optimal cleaning and prevent freezing, do not top up or replace this fluid with water.
Reservoir capacities:
- windscreen washer fluid: approximately 3.5 litres,
- windscreen and headlamp washer fluid: approximately 6.15 litres.
Diesel additive level (Diesel with particulate filter)
The minimum level of this additive is indicated by the service warning light coming on, together with an audible signal and a message on the multifunction display.
Topping up
This additive must be topped up promptly and only by the CITROËN network.
Used products
! Avoid prolonged skin contact with used oil and fluids.
Most of these fluids are harmful to health and some are highly corrosive.
Do not pour used oil and fluids down drains or onto the ground. Drain used oil into the containers provided for this purpose at the CITROËN network.Test yourself
A quick Citroen C5 Aircross quiz: every answer comes with an explanation and a link to the manual page.