Oil pump parts
1. Remove the spring clamp from the oil pick-up tube, take out the filter and rubber support.
2. Mark the position of the mounting bracket, loosen and remove the bolts from the sensor housing.
3. Separate the casings and remove the driven gear, marking its position.
4. Wash the parts in kerosene and dry them. Check the gears and end plates for wear and, if it is too great, replace the oil pump. If the parts are still usable, put them back in place in the reverse order and tighten the bolts.
(Publication taken from an online resource: «Mercedesman.ru»)
5. Bleed the oil pump by turning the drive shaft counterclockwise and pouring oil into the sensor tube.