2022 XC90 Volvo Brakes
Brake fluid – specifications
Brake fluid is the medium in a hydraulic brake system that is used to transfer pressure from e.g. a brake pedal via a master brake cylinder, which in turn acts on the brake callipers.
Prescribed grade: Volvo Original or equivalent fluid compliant with a combination of Dot 4, 5.1 and ISO 4925 class 6.
Note
It is recommended that brake fluid is changed or filled by an authorized Volvo workshop.
Brake functions
The car’s brakes are used to reduce the speed or prevent the car from rolling.
Besides the foot brake and parking brake, the car is equipped with several automatic brake assist functions. These can assist the driver by not needing to keep his/her foot on the brake pedal when at a traffic light, or when starting on an uphill gradient.
Depending on the car’s equipment, the following auto braking functions are available:
- Automatic brake when stationary (Auto Hold)
- Hill start assist (Hill Start Assist)
- Auto braking after a collision
- City Safety
- Hill descent control (Hill Descent Control)
Automatic braking when stationary
Automatic brake when stationary (Auto hold) means that the driver can release the brake pedal while maintaining braking effect when the car has stopped at traffic lights or a junction.
When the car has stopped, the brakes are activated automatically. The function can use either foot brake or parking brake to hold the car stationary and it works on all gradients. When driving off, the brakes are released automatically if the driver is wearing the seatbelt and/or the driver’s door is closed.
Note
When braking to a standstill on an uphill or downhill slope, the brake pedal should be depressed a little harder before being released to ensure the car does not roll.
The parking brake is activated if
- the car is switched off
- the driver’s door is opened
- the driver’s seatbelt is unbuckled
- the car has been stationary for a longer time (5-10 minutes).
Auto hold can also change over to the parking brake in other situations.
Symbols in the driver display
| Symbol | Specification |
|---|---|
 |
The symbol is illuminated when the function uses the foot brake to keep the car stationary. |
 |
The symbol is illuminated when the function uses the parking brake to keep the car stationary. |
Activating and deactivating the automatic brake at a standstill
The automatic brake function at a standstill is activated using the button in the tunnel console.
Press the button in the tunnel console to activate or deactivate the function.
The indicator in the button illuminates when the function is activated. The activated function remains even when the car is started next time.
Applicable when switching off
If the function is active and holds the car with the foot brake (A-symbol illuminated in the driver display), the brake pedal must be depressed at the same time as the button is depressed in order to deactivate.
- The function remains deactivated until it is reactivated.
- When the function is deactivated, hill start assist (HSA) remains active to prevent the car from rolling backwards when starting on an uphill gradient.
Auto braking after a collision
In the event of a collision in which the activation level is reached for the pyrotechnic seatbelt tensioners or airbags, or if a collision with a large animal is detected, the car’s brakes are automatically applied. This function is to prevent or reduce the effects of any subsequent collision.
After a serious collision there is a risk that it is no longer possible to control and steer the car. In order to avoid or mitigate a possible further collision with a vehicle or an object in the vehicle’s path, the auto braking system is activated automatically and brakes the car in a safe manner.
Brake lights and hazard warning lights are activated during braking. When the car has stopped, the hazard warning lights continue to flash and the parking brake is applied.
If braking is not appropriate, e.g. if there is a risk of being hit by following traffic, the system can be overridden by the driver depressing the accelerator pedal.
The function assumes that the brake system is intact after the collision.
Help when starting on a hill
Hill start assist (HSA(Hill Start Assist)) prevents the car from rolling backwards when starting on an uphill gradient. When reversing uphill, it prevents the car from rolling forwards.
The function means that the pedal pressure in the brake system remains for several seconds while the driver’s foot is moved from brake pedal to accelerator pedal.
The temporary braking effect releases after several seconds or when the driver starts to drive away.
The Hill Start Assist is activated when stopping on a sleep slope. The function is available even when the automatic braking when stationary (Auto hold) function is deactivated.
Regenerative braking
(Option/accessory)
The car recovers kinetic energy during braking in order to reduce fuel consumption and emissions.
The battery symbol is shown in the driver display when the car is generating power for the battery.
The function is available in all drive modes together with gear position D or M.
Activating brake regeneration
Brake regeneration is activated by gentle pressure on the brake pedal or during engine braking.
Regeneration increases during engine braking when manual gearshift mode M is selected.
Low speed control
(Option/accessory)
The low speed control function (LSC(Low Speed Control)) facilitates and improves traction for driving off-road and on slippery surfaces, such as with a caravan on grass or a boat trailer on a launch ramp.
The function is included in drive mode Off Road.
The function is adapted for off-road driving and driving with a trailer at low speed, up to approx. 40 km/h (25 mph).
Low speed control prioritises low gears and traction. If the car is all-wheel drive, the motive force is distributed evenly in order to provide as good traction as possible on all wheels and to reduce the risk of wheel spin. The accelerator pedal is less responsive in order to facilitate traction and speed control at low speed.
The function is activated together with hill descent control, (HDC(Hill Descent Control)) which means that speed down steep hills can be controlled with the accelerator pedal, reducing the need to use the brake pedal. The system facilitates a low and even speed while driving on steep downhill gradients.
Note
When LSC with HDC is activated, the feel of the accelerator pedal and engine response are changed.
Note
The driving mode is not designed to be used on public roads.
Note
The function is deactivated when driving at higher speeds and must be reactivated at a lower speed, if required.
Hill descent control
(Hill Descent Control)
Hill descent control (HDC(Hill Descent Control)) is a low speed function with enhanced engine braking. The function makes it possible to increase or reduce the car’s speed on steep downhill gradients using only the accelerator pedal, without using the foot brake.
The function is included in drive mode Off Road.
Hill descent control is adapted for off-road driving at low speeds and facilitates driving on steep downhill gradients with difficult surfaces. The driver does not need to use the brake pedal, but can instead focus on steering.
Warning
HDC does not work in all situations but is designed merely as a supplementary aid.
The driver always bears ultimate responsibility for ensuring that the vehicle is driven safely.
Function
Hill descent control allows the car to roll at inching speed both forward and backward, assisted by the brake system. The speed can be increased by using the accelerator pedal. When the accelerator pedal is then released the car slows back down to crawling speed, regardless of the gradient of the hill and without the need for the foot brake to be used. The brake lights are switched on when the function is operating.
The driver can brake and reduce crawling speed, or stop the car at any time by using the foot brake.
The function is activated together with low-speed control (LSC(Low-Speed Control)) which facilitates driving and improves traction for driving off-road and on slippery surfaces. The systems are designed for use at low speed, up to approx. 40 km/h (25 mph).
Points to remember when driving with HDC
- If the function is disabled while driving on a steep downhill gradient, the braking effect will gradually decrease.
- HDC can be used in gear positions D, R, and with 1st or 2nd gear with manual gear changing.
- It is not possible to change to 3rd gear or higher with manual gear changing.
Note
When LSC with HDC is activated, the feel of the accelerator pedal and engine response are changed.
Note
The driving mode is not designed to be used on public roads.
Note
The function is deactivated when driving at higher speeds and must be reactivated at a lower speed if required.