overheating MERCEDES-BENZ GLS 2017 Owners Manual

This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage
is not covered by the Mercedes-Benz war-
ranty.
Do not depress the brake pedal continuously
while the vehicle is in motion, e.g. causing the
brakes to rub by constantly applying light pres-
sure to the pedal. This results in excessive and
premature wear to the brake pads.
Use the left-hand steering wheel paddle shifter
to shift into a lower gear in good time on long
and steep downhill gradients. This is especially
important if the vehicle is laden.
This also applies if you have activated cruise
control, the speed limiter or Distance Pilot
DISTRONIC.
This will use the braking effect of the engine, so
that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
Heavy and light loads
G WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This
increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first time. This may also occur after the vehicle has
been washed or driven through deep water.
You then have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance. R
Brake occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so. R
Carefully depress the brake pedal and the
beginning and end of a journey. R
Maintain a greater distance to the vehicle
ahead.
Servicing the brakes
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
! A function or performance test should only
be carried out on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult a qualified spe-
cialist workshop in advance. You could oth-
erwise damage the drive train or the brake
system.
! Because ESP ®
is an automatic system, the
engine and ignition must be switched off
(SmartKey in position 0 or 1 or Start/Stop
button in position 0 or 1 ) when the electricDriving tips 165
Driving and parking Z

R
you activat e th e Offroad Plus progra m (vehi-
cle s wit h th e Off-Road Engineerin g package)R
you shift th e transmission to position N while
drivin g
If cruise control is deactivated, you will hear a
warnin g tone . You will see th e Cruise Con ‐
tro l Off message in th e multifunction display
for approximately fiv e seconds.
i Whe n you switch off th e engine, th e last
speed store d is cleared .
Distance Pilot DISTRONIC
Gene ra l notesDistanc e Pilo t DISTRONI C regulates th e speed
and automatically help s you maintai n th e dis-
tance to th e vehicl e detecte d in front. Vehicles
are detecte d wit h th e aid of th e rada r sensor
system. Distanc e Pilo t DISTRONI C brakes auto-
matically so that th e set speed is no t exceeded .
You mus t select a lower gear in goo d time on
lon g and steep downhill gradients , especially if
th e vehicl e is laden or towin g a trailer . By doin g
so, you will mak e use of th e brakin g effec t of th e
engine. This relieves th e load on th e brak e sys-
te m and prevents th e brakes from overheating
and wearin g to o quickly.
If Distanc e Pilo t DISTRONI C detects that there is
a ris k of a collision , you will be warned visually
and acoustically. Without your intervention , Dis-
tance Pilo t DISTRONI C canno t preven t a colli-
sion . An intermittent warnin g tone will then
soun d and th e distanc e warnin g lamp will ligh t
up in th e instrumen t cluster. Brake immediately
in order to increase th e distanc e to th e vehicl e in
fron t or tak e evasive action provided it is saf e to
do so.
Fo r Distanc e Pilo t DISTRONI C to assist you
when driving, th e rada r sensor system mus t be
operational.
Dis tanc e P
ilo t DISTRONI C operate s in th e range
between 0 mph (0 km/h) and 12 0 mph
(20 0 km/h).
Do no t use Distanc e Pilo t DISTRONI C while driv-
in g on roads wit h steep gradients .
Since Distanc e Pilo t DISTRONI C transmit s rada r
waves, it can resemble th e rada r detectors of
th e responsibl e authorities. You can refer to th e
relevan t chapter in th e Operator' s Manual if
question s are asked about this. i US A only:
This device has been approve d by th e FCC as
a "Vehicular Radar System". The rada r sensor
is intended for use in an automotive rada r
system only. Removing, tamperin g with, or
altering th e device will voi d any warranties,
and is no t permitte d by th e FCC. Do no t tam -
per with, alter, or use in any non-approve d
way.
An y unauthorize d modification to this device
could voi d th e user’s authorit y to operate th e
equipment.
i Canada only: This device complies wit h
RSS-210 of Industry Canada. Operation is
subjec t to th e followin g tw o conditions:
1. This device may no t caus e harmful inter-
ference , and
2. This device mus t accept any interferenc e
received, includin g interferenc e that may
caus e undesired operation of th e device .
Removal, tampering, or altering of th e d evice
w
ill voi d any warranties, and is no t permitted.
Do no t tamper with, alter, or use in any non-
approve d way.
An y unauthorize d modification to this device
could voi d th e user's authorit y to operate th e
equipment.
Imp or tant safety notes
G WARNIN G
Distanc e Pilo t DISTRONI C does no t reac t to :R
people or animals R
stationary objects on th e road, e.g. stoppe d
or parked vehicles R
oncomin g vehicles and crossin g traffic
As a result , Distanc e Pilo t DISTRONI C may
neither giv e warnings no r interven e in suc h
situations. There is a ris k of an accident.
Always pay careful attention to th e traffic sit -
uation and be read y to brake.
G WARNIN G
Distanc e Pilo t DISTRONI C canno t always
clearly identify other roa d user s and complex
traffic situations.174
Driving systems
Driving and parking

R
Do not install hired trailer couplings or other
detachable trailer couplings on the bumpers
of your vehicle. R
If you no longer need the ball coupling,
remove it from the ball coupling recess. This
will reduce the risk of damage to the ball cou-
pling.
When towing a trailer, set the tire pressure on
the rear axle of the towing vehicle for the max-
imum load. You will find the values in the tire
pressure table in the fuel filler flap of the vehicle
( Y
page 364).
Please note that when towing a trailer, the fol-
lowing driving systems have limited availability
or are not available at all: R
Parking Assist PARKTRONIC ( Y
page 190)R
Blind Spot Assist ( Y
page 207)R
Active Lane Keeping Assist ( Y
page 213)
On vehicles without level control, the height of
the ball coupling will alter according to the load
placed on the vehicle. If necessary, use a trailer
with a height-adjustable drawbar.
You will find installing dimensions and loads
under "Technical data" ( Y
page 387).
Driving tips Observe the information on ESP ®
trailer stabili-
zation ( Y
page 68) and on pulling away with a
trailer ( Y
page 141).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check the
trailer's documents to see what the maximum
permissible speed is. Observe the legally pre-
scribed maximum speed in the relevant country.
For certain Mercedes-Benz vehicles, the maxi-
mum permissible rear axle load is increased
when towing a trailer. See "Technical data" to
find out whether this applies to your vehicle
( Y
page 387). If you utilize any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not exceed
a maximum speed of 60 mph (100 km/h) for
reasons concerning the operating permit. This
also applies in countries in which the permissi-
ble maximum speed for vehicle/trailer combi-
nations is above 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer. Use the left-hand steering wheel paddle shifter
to shift into a lowe r g ear in good time on long
a
nd steep downhill gradients.
This also applies if you have activated cruise
control or Distance Pilot DISTRONIC.
This will use the braking effect of the engine, so
that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly. If you need additional
braking, depress the brake pedal repeatedly
rather than continuously.
Driving tips If the trailer swings from side to side: X
Do not accelerate. X
Do not counter-steer. X
Brake if necessary. R
Maintain a greater distance from the vehicle
in front than when driving without a trailer. R
Avoid braking abruptly. If possible, brake gen-
tly at first to allow the trailer to run on. Then,
increase the braking force rapidly. R
The values given for gradient-climbing capa-
bilities from a standstill refer to sea level.
When driving in mountainous areas, note that
the power output of the engine and, conse-
quently, the vehicle's gradient-climbing capa-
bility, decreases with increasing altitude.
Installing the ball coupling
G WARNING
If the ball coupling is not correctly installed
and secured, it can come loose during the
journey and endanger other road users. There
is a risk of an accident and injury.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
G WARNING
If the ball coupling is not installed correctly or
not secured with the bolt provided and the
corresponding spring cotter, the trailer may
come loose. There is a risk of an accident.Towing a trailer 223
Driving an d parking Z

Gasoline engines MB-Freigabe or
MB-Approval
All models
229.5
Diesel engines MB-Freigabe or
MB-Approval
GLS 350 d 4MATIC
228.51, 229.31,
229.51, 229.52
Mercedes-AMG vehicles: only use SAE 0W-40
or SAE 5W-40 engine oils.
i MB approval is indicated on the oil contain-
ers.
Filling capacities The following values refer to an oil change
including the oil filter.
Model Capacity
GLS 350 d 4MATIC
8.5 US qt (8.0 l)
GLS 550 4MATIC
Mercedes ‑ AMG
vehicles 9.0 US qt (8.5 l)
Al l ot her models
7.4 US qt (7.0 l)
Ad ditives
! Do not use any additives in the engine oil.
This could damage the engine.
Brake fluid
G WARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake
fluid is too low, vapor pockets may form in the
brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals. Comply with the important safety notes for ser-
vice products when handling brake fluid
( Y
page 378).
The brake fluid change intervals can be found in
the Maintenance Booklet.
Only use brake fluid approved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval 331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or
on the Internet at
http://bevo.mercedes-benz.co m.
i Have the brake fluid regularly replaced at a
qualified specialist workshop in accordance
with the replacement intervals and the
replacement confirmed in the Maintenance
Booklet.
Coolant
Important safety notes
G WARNING
If antifreeze comes into contact with hot com-
ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
! Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the replace-
ment confirmed in the Maintenance Booklet.382
Service products and filling capacities
Technical data