DAF LF45, LF55 Series. Manual - part 515
7
LF45/55 series
General
RESERVOIR AND LINES
1-3
1.3 OPERATION OF RESERVOIR, VERSION WITHOUT STEERED TRAILING
SWIVEL AXLE
General
A filter element is fitted in the reservoir. This
cannot be replaced. If the filter element needs to
be replaced (e.g. because the steering oil is
very dirty), the whole reservoir must be
replaced.
The return oil is partially filtered by the filter.
The filter is not fitted in the supply pipe, as the
resistance of the filter means that the filter
element and reservoir would need to be very
large.
When working on the steering gear,
prevent dirt from entering the
reservoir and the pipes. When the
steering oil is drawn in it is
unfiltered, freely allowing dirt to
enter the steering gear.
A by-pass valve is fitted under the filter.
When the engine is at idling speed and the
steering pump output is limited, the by-pass
valve is closed. In this case, all return oil passes
through the filter. If the steering pump output is
at maximum, approx.
1
/
3
of the oil will pass
through the filter and
2
/
3
will flow directly into the
reservoir through the by-pass valve.
As the speed at which the oil circulates is very
high, eventually all the oil will pass through the
filter and the oil will be filtered sufficiently
frequently.
The fact that the oil is only partially filtered
means that a small filter element can be used.
A dipstick is fitted in the top of the reservoir with
a minimum and maximum oil level mark.
There is a small air-bleeder hole in the rubber
cap of the dipstick. This hole must always be
open, otherwise the return pressure will become
too high.
Max.
Min.
S7 00 051
5
ᓻ 200322