Vaz -21213 Repair Manual page 40

Fig.2-68. Basic dimensions of the oil pump components and associated parts
Removal and refitting. When only the oil pump requires recon-
ditioning, remove it from the vehicle (Refer to section «Engine -
removal and refitting»), place it on the turning stand, drain the oil
from the sump, turn over the engine and remove the sump. Undo
the oil pump bolts and remove the pump complete with the intake
manifold assembly.
Refitting is the reversal order of removal.
Dismantling and reassembly. Position the oil pump in vice
taking care not to damage the pump housing, then:
- undo the bolts and remove the intake manifold complete
with the oil pressure relief valve;
- remove cover 3 (Fig.2-69) and withdraw the pump shaft
complete with the inner and outer gears from the housing.
To reassemble the pump, position the pump in vice and carry
out the following operations:
- refit the inner gear with the shaft, then the outer gear;
- refit the pump cover, pressure relief valve with the spring and
bolt the intake manifold assembly to the pump body.
Note. On completing the pump assembly, turn the inner gear
by hand to check the gears are running smoothly, without jerks or
seizures.
Inspection. After dismantling, wash all components in kero-
sine or petrol, blow dry with compressed air, then check the pump
40
housing and cover for cracks, renew when applicable.
Using feeler blades, check the backlash in the gears and the
radial play (Fig.2-70) to be respectfully 0.15 mm (maximum per-
missible value is 0.25 mm) and 0.11-0.18 mm (maximum permis-
sible value is 0.25 mm). If the tolerances are exceeded, then the
gears or pump housing should be renewed.
Using a feeler gauge and a straight-edge (Fig. 2-71), check
the axial clearance to be 0.066-0.161 mm (maximum permissible
value is 0.20 mm). When the clearance is over 0.20 mm, renew
the gears or pump housing whichever is worn out.
Having taken the measurements, determine the clearance
between the outer gear and its axle to be 0.017-0.057 mm (maxi-
mum permissible value is 0.10 mm) and the clearance between the
oil pump shaft and the housing bore to be 0.016-0.055 mm (maxi-
mum permissible value is 0.10 mm). Renew any worn parts when
the tolerances exceed the values specified.
Checking the pressure relief valve. Always inspect the
pressure relief valve during the oil pump repair. Draw special
attention to the valve surfaces and bores in the intake manifold
assembly, since possible contamination or sediments on the mat-
ing surfaces can result in the valve seizures.
The mating valve/pump cover surfaces should show no dents
or flash to prevent a drop of oil pressure in the lubrication system.
Check the relief valve spring tension against the values as
given in Fig.2-72.