11 - 2
Auxiliary Pump
The numerical sequence shown on the illustration is intended
as a guide to dismantling.
For assembly the sequence should be reversed.
Dismantling
Remove coupling A if still fitted.
Hold the body in a soft jawed vice with the mounting flange
uppermost. Mark all parts to ensure correct alignment when
assembling. Discard all seals and sealing rings.
Clean all parts in light aromatic kerosene, examine for
damage and wear.
Damaged or worn parts must be renewed.
Inspection
It is normal for the gears to have cut a slight track in the body
bore on the inlet side. The gear track wear can not be
measured accurately but will be related to bearing wear.
Examine the bearing bores C which are coated during
manufacture with PTFE. If the grey PTFE is worn through so
that the bronze base is visible, the complete pump must be
renewed.
Renew the pump if the bearings are scored or if the gear side
faces are chipped or damaged. DO NOT use any abrasives
on the bearings or gears as this would destroy critical
manufacturing dimensions.
Assembly
Fit the pressure loading ring/backing ring 10 and sealing
rings 11 to the flange 2 and cover 8. A little grease (JCB MPL
Grease) in the grooves will help retain them.
Hold the flange 2 in a soft jawed vice with the sealing rings
facing upwards and assemble the body 3. Ensure that the
body cut-in track corresponds to the inlet side of the flange.
Assemble the gear/bearing pack components 4, 5, 6 and 7
separately. It is important to return the flange end bearing 6
to the flange end of the unit, otherwise internal leakage can
occur due to bedding in. Ensure that the bearing face
recesses B are adjacent to the gear faces and that the
relieved radii are both towards the pump outlet.
Lightly lubricate the body bore and bearings, then push the
gear/bearing pack into the body.
Fit the cover 8, ensuring the inlet side is in the correct
position. Torque tighten bolts 1 to 61 - 68 Nm (45 - 50 lbf ft,
6.2 - 7.0 kgf m).
If the inlet adapter is disturbed, fit a new ‘O’ ring and tighten
to 115 - 145 Nm (85 - 107 lbf ft, 11.7 - 14.8 kgf m). Do not
overtighten.
Testing
Install the pump onto a suitable test rig and test as follows.
Test Data
Oil Viscosity 40 - 45 cSt at 50 °C, (122 °F)
Oil Temperature 45 - 50 °C (113 - 122 °F) at pump inlet
Test Speed 1500 rev/min nominal
Run pump initially off load and check for leaks. Increase
pressure in stages of 40 bar and allow to run for 1 minute at
each stage. This will allow components to readjust and flow
readings will indicate if re-build is correct. Check pump output
under the following conditions.
Pressure 230 bar (3335 lb/in
2
, 230 kg/cm
2
)
Minimum Flow 22.0 litre/min
Section E
Hydraulics
9803/8500
Section E
11 - 2
Issue 2*
Pumps
139690
*
To Next Page
Loading...
