Contents: Disassembly ⇓ Assembly ⇓
Disassembly
Remove the oil pump from the engine. To remove the pump, it is necessary to disconnect and remove the camshaft drive components (lower part), as well as an oil pan.
Clean the removed oil pump from dirt, wash the external elements of the pump and covers.
Disconnect the oil receiver from the pump body (if not already disconnected).
After unscrewing the mounting bolts, detach the pump housing from the front cover of the cylinder block.
Internal gear pump:
- After unscrewing the bolts (1), remove the cover (2).
- Remove the pump gears
External gear pump:
Remove the pressure reducing valve (plug, spring and valve).
Clean all parts from dirt, oil and deposits.
Stubborn deposits can be removed by soaking the parts in solvent.
Caution: To avoid poisoning, avoid inhaling vapors and contact of the solvent with exposed areas of the body.
Checking oil pumps with internal gear engagement
Measurement locations
A - axial clearance;
B - clearance between the outer side of the gear and the housing hole;
B - gap between gear teeth.
Check for foreign particles and determine the cause of their entry.
Check the pump body and cover for cracks and scratches. If there are any defects, replace the housing.
Reinstall both gears into the pump housing and check the axial clearance between the top side of the pump housing and the top side of the gears by applying a steel ruler and measuring it with a feeler gauge as shown in the figure. The maximum allowable clearance is 0.10 mm between the ruler and the internal gear and 0.15 mm between the ruler and the external gear of the pump. If necessary, the axial clearance can be slightly reduced by sanding the pump body on a straightening plate using sandpaper.
Insert a feeler gauge between the outside of the pump drive outer gear and the hole in the housing. The gap should not exceed 0.20 mm.
The gap between adjacent teeth should be less than 0.18 mm.
If the measured values exceed the permissible limits due to wear, either the pump gears or the oil pump housing must be replaced.
Check the pressure relief valve for scratches and signs of sticking. Dents and burrs should be removed with a fine sanding block.
Check the pressure reducing valve spring for loss of elasticity and bending. If there are any defects, replace the springs.
Check the inlet pipe assembly with the filter (mesh) for leaks and damage to the mesh inlet filter.
Check the gears for chipped material, scoring and wear.
Features of testing oil pumps with external gear engagement
After installing the gears and front cover, check that the gears rotate smoothly.
Check the axial clearances of the gears. Required values: leading gear no more than 0.14 mm; driven gear no more than 0.12 mm.
Check the clearances between the gears and the pump body. Required value: 0.1 mm.
Assembly
Lubricate all internal parts of the pump with engine oil.
Install the pump gears by aligning the marks.
Caution: To avoid engine damage, coat all cavities of the oil pump with grease before installing the gears to ensure oil suction and supply to the engine lubrication system.
Install the cover and gasket.
Caution: To avoid engine damage, use only original factory gaskets.
Install the pressure reducing valve and spring
Using a torque wrench, tighten the pressure reducing valve plug to 30 Nm.
When repairing the oil pump, replace the oil filter and replace the engine oil with fresh oil.
Caution: If the oil pressure is not immediately established at the normal level, remove the oil pan and check the connection of the pump to the inlet pipe. If necessary, dismantle and disassemble the pump, fill the pump cavities and reassemble the pump. Running the engine without oil pressure will cause serious engine damage.