Severe Strain On The Brake System; If The Brake Power-Assist Does Function; Trailer Towing - Volvo 850 User Manual

1994 Volvo 850
The system performs a self-diagnostic test when the vehicle is started and at 20 mph (30 km/h). The
brake pedal will pulsate several times and a sound may be audible from the ABS control module. This is
normal.
To obtain optimal effect from the ABS system, constant pressure should be kept on the brake pedal
while the system is modulating the brakes.
The switching of the ABS modulator will be audible and the brake pedal will pulsate at this time. Please
be aware that ABS does not increase the absolute braking potential of the vehicle. While control will be
enhanced, ABS will not shorten stopping distances on slippery surfaces.
Moisture on brake discs and brake pads affects braking.
Driving in rain and slush or passing through an automatic car wash can cause water to collect on the
brake discs and pads. This will cause a delay in braking effect when the pedal is depressed. To avoid
such a delay when the brakes are needed, depress the pedal occasionally when driving through rain,
slush etc. This will remove the water from the brakes. Check that brake application feels normal! This
should also be done after washing or starting in very damp weather.

Severe strain on the brake system

The brakes will be subject to severe strain when driving in mountains or hilly areas or towing. The speed
is usually low which means that the cooling of the brakes is less efficient than when driving on level
roads. To reduce the strain on the brakes it is advisable not to use the brakes excessively. Instead, shift
into a lower gear, position 3 or in some cases, L(automatic transmission) and let the engine help with the
braking. Do not forget that, if you are towing a trailer, the brakes will be subjected to greater load than is
normal.

If the brake power-assist does function

The power assist to the brakes functions only when the engine is running. When the car is moving
without the engine running, the brake pedal pressure required to stop the car is increased by 3-4 times
and the brake pedal feels stiff.
pg. 4:17 Trailer towing
When preparing for trailer towing, observe the following:
Use a trailer which meets Federal Safety Standards for rear end collisions (FMVSS 301-75). For
trailer weights exceeding 2000 lbs. (908 kg), use only a trailer hitch offered as a Genuine Volvo
accessory.
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