Mercedes-Benz 201.024 Service Manual page 189

The hydraulic valve clearance compensating
elements consist of the following components:
Set bolt (64) with oil reservoir chamber (a)
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as well as return and venting bores (c) and a
ball valve, consisting of a 5 mm 0 ball (63),
telescopic type ball bearing traveler
compression spring (62).
Guide sleeve (59) with working chamber (b),
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compression spring (60) and sealing cap
(65).
The element can drop completely when the
engine is not running and the cam tip presses
against the rocker arm and thus also against the
element. Oil expelled from the working chamber
(b) flows via the annular gap (built-in clearance
between guide sleeve and set bolt) to the
reservoir chamber (a).
When the cam tip moves away from the rocker
arm, the set bolt (64) is relieved of load and the
compression spring (60) presses the set bolt
upwards until the rocker arm contacts the cam.
The vacuum, arising from the upward movement
of the set bolt, opens the ball valve, and oil flows
out of the reservoir chamber (a) into the working
chamber (b).
As soon as the cam presses against the rocker
arm and thus loads the set bolt, the ball valve
closes. The oil in the working chamber acts as
an " hydraulically rigid connection" and the
respective valve is opened.
When the engine is running, depending on
engine speed and cam position, the set bolt is
only pressed slightly downwards.
05.0906 - 211/4
5 8 -
5 5 -
(61)
and
EXIT