MASSEY FERGUSON 5400 - General; Low Flow Rate, Low Pressure Circuit

Massey Ferguson 5400 - Issue 1.a
09A01.3
Description of circuit open centre 57 l/mn
A . General
The Open Centre hydraulic circuit is comprised of two
separate circuits.
These two circuits are supplied by a two-stage gear
pump (1) (Fig. 1) fitted on the internal face of the
right-hand hydraulic cover. The pump sucks transmis-
sion oil from the common tank formed by the centre
housing and the gearbox through a 150 micron
filter (1) (Fig. 2), also fitted on the right-hand cover.
One or two 15 micron main filter(s) (39) (depending on
option) and a clogging indicator (40) are fitted on the
low flow rate circuit upstream from the Orbitrol stee-
ring spool valve (Fig. 2).
The hydraulic pump is driven by the ring gear of the
PTO clutch unit (Fig. 1).
B . Low flow rate, low pressure
circuit
REMINDER : The first stage of the pump supplies the
hydrostatic steering where pressure can reach
170 bar.
Hydraulic flow
After supplying of the Orbitrol steering spool valve as
required, the oil is directed to the left-hand cover atta-
ched to the centre housing.
This cover performs several low pressure functions.
It ensures:
- operating pressure for the various transmission
components via a 17 bar valve (2) (Fig. 3) fitted
downstream from the Orbitrol unit;
- cooling and lubrication of the gearbox and connected
components;
- booster pressure for brake master cylinders (exclu-
ding MERITOR master cylinders)
Fig. 1
Fig. 2
Fig. 3