Mercedes-Benz OM 904 LA, Operating Instructions Manual

Page: 67 / 112

Test toler-
ance Inlet
valves +/- 0.05 mm
Exhaust
valve +/- 0.10 mm
The tolerance is only applicable for checking,
not as a valve clearance setting.
Adjust the valve clearance when the engine
is cold (at least 30 minutes after stopping the
engine, even if it has only been operated for
a brief period).
G
WARNING
If not properly secured, a vehicle might acci-
dentally be set in motion, knocking somebody
down or trapping them or causing an accident
and injuring you or others.
R
Always prevent the vehicle from rolling
away by applying the parking brake and, if
necessary, using chocks.
R
Shift the transmission into neutral.
R
Only turn the engine over using the crank-
ing device provided for this purpose.
G
WARNING
If the engine starts automatically, there is a
risk of injury by limbs being crushed between
the moving parts.
Secure the engine against unintentional start-
ing before carrying out maintenance or repair
work.
G
WARNING
The engine becomes very hot while it is run-
ning and remains so for some time after it has
stopped. It will cause burns if touched.
Before starting any work on the engine, allow
all engine parts to cool down, or wear suitable
gloves and items of clothing to protect your-
self from being burned on hot engine compo-
nents.
Removing and fitting the cylinder head
covers
Example: cylinder head cover
:
Engine ventilation hose
;
Cylinder head cover
=
Bolt
?
Sealing washer
A
Seal
X
If excessively dirty, clean the cylinder head
covers before removal.
X
Remove engine ventilation hose
:
from
cylinder head cover
;
.
X
Remove cylinder head cover
;
.
X
Remove gasket
A
between cylinder head
cover
;
and the cylinder head.
X
Clean the mating surfaces of cylinder head
cover
;
and the cylinder head.
Work schedules
65
Notes on maintenance
Z