Mercedes-Benz 300 SD 1978, Owner'S Manual

Page: 43 / 79

Safe D rivin g
in stru m e n t clu ste r com es on, either
the brake fluid level in the reservoir is
too low or the bra ke system is leaking.
Brake pad wear may cause a shortage
of brake flu id in the reservoir. Install
only brake pads recom m ended by us.
I , If o ther than re com m ended brake
9 m , pads are installed, the braking
p ro p e rties of the vehicle can be
affected to an extent that the safety is
substantially im paired.
Brake Pad W ear Indicator
The brake pad w ear in d ic a to r in the
in stru m e n t clu ste r com es on when the
key in the steering lock is turned to
driving position “ 2” and itm u s tg o o u t
when the engine is running. If the
in d ica tor lights up during braking or
d riving, this show s that the fro n t wheel
brake pads are w orn down.
Have brake system checked in a
MERCEDES-BENZ service station as
soon as possible.
Brake Fluid
During the course of the ope ra tio n of
the vehicle, the boiling po in t of the
brake flu id is co n tin u o u sly being
reduced th ro u g h the a b so rp tio n of
m oisture fro m the atm osphere. U nder
extrem ely hard o perating co nditions,
this m oisture co n te n t can lead to the
fo rm a tio n of va p o r in the system thus
reducing the syste m ’s efficiency. The
brake fluid m ust th e re fo re be
replaced annually, pre fe ra b ly in the
spring. It is re com m ended to use only
b ra k e flu id approved by MERCEDES-
BENZ. Y our MERCEDES-BENZ
dealer w ill p ro vid e you with a d d ition a l
inform ation.
Charge Indicator Light
S hould the charge in d ica to r lig h t fail
to com e on p rio r to starting when the
ignition key is in position "2 ” or should
it fail to go out after starting or du rin g
operation, this indicates a fa u lt w hich
m ust be repaired at a MERCEDES-
BENZ service station as soon as
possible.
Oil Pressure Gauge
The oil p ressure may d ro p at idle
speed to 7.1 psi (0.5 k p /s q .c m ) if the
engine is at operating tem perature.
This will not je o p a rd ize its operational
reliability. Pressure must, however,
rise im m e d ia te ly upon acceleration.
Coolant Tem perature Gauge
Due to the pressurized cooling
system , the c o o la nt only starts boiling
at a te m p e ra tu re of approx. 257° F
(125° C) with an antifreeze-blended
co o la nt fill p rotecting down to -22° F
(-30° C) (see also “ Fuels, C oolants,
Lubricants, etc.” ).
The co o la nt te m p e ra tu re may rise to
the red m arking in the case of high
a m b ie n t te m p e ra tu re s and when
travelling in m ountainous terrain.
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