3.13.2. Oil pump

Removal and installation
For removal of the oil pump:
— put the car on a viewing ditch or the elevator, disconnect wires from the rechargeable battery and merge oil from an engine case;
— remove an engine mudguard;
— turn off nuts, the fixing pillows of a forward engine mount to a cross-piece, and slightly raise the engine a jack or a waist that hairpins of pillows left cross-piece openings;
— remove an engine case;
— remove the oil pump together with a reception branch pipe.
Carry out operations on installation of the oil pump on the engine in the sequence, the return to removal.

Dismantling and assembly
Fix the oil pump in a vice carefully not to damage the case, and then:
— turn off bolts and remove a reception branch pipe together with the reducing valve of pressure of oil;

Fig. 3-70. Dismantling of the oil pump: 1 — the reducing valve; 2 — a spring; 3 — a cover; 4 — the case; 5 — the roller

— uncover 3 (fig. 3-70) of a pump housing and take out from the case the pump roller with the leading gear wheel and the conducted gear wheel.
For assembly carefully fix the pump in a vice and execute operations in the following order:
— establish in a pump housing the leading gear wheel with shaft, and put on the conducted gear wheel an axis in the case;
— establish a case cover, the reducing valve with a spring and attach a reception branch pipe to a pump housing.

...... NOTE
After assembly of the pump at a provorachivaniye of the leading roller a hand, gear wheels have to rotate smoothly and without jamming.

Check of details of the pump
After dismantling wash out all details of the pump kerosene or gasoline, blow a stream of compressed air, and then examine the case and a cover of the pump; in the presence of cracks of a detail replace.

Fig. 3-71. Check of a radial gap in the oil pump

Check a set of probes gaps between teeths of gear wheels, and also between outer diameters of gear wheels and walls of a pump housing (fig. 3-71) which have to be respectively 0,15 mm (maximum permissible 0,25 mm) and 0,11–0,18 mm (maximum permissible 0,25 mm). If gaps exceed extreme values, then replace gear wheels, and if necessary and a pump housing.

Fig. 3-72. Check of an axial gap in the oil pump

The probe and ruler (fig. 3-72) check a gap between end faces of gear wheels and the plane of the case which has to be equal to 0,066-0,161 mm (maximum permissible 0,2 mm). If the gap is more than 0,2 mm, replace gear wheels or a pump housing depending on what underwent wear.
Having measured details, define a gap between the conducted gear wheel and its axis which has to be 0,017–0,057 (maximum permissible 0,1 mm), and also between shaft of the pump and an opening in the case, this gap has to be 0,016–0,055 (maximum permissible 0,1 mm). If gaps exceed limit — replace worn-out details.

Check of the reducing valve
At repair of the oil pump check the reducing valve. Pay attention to the surfaces of the valve and case as possible pollution or deposits on the interfaced surfaces can lead to jamming. On the interfaced surface
the valve should not be забоин and agnails which can lead to reduction of pressure in system.

Fig. 3-73. A specification for check of a spring of the reducing valve

Check elasticity of a spring of the reducing valve, comparing the obtained data with provided on fig. 3-73.