Figure 302. Fastening the vacuum pump to the front of the engine: 1 - tension roller (if it is installed); 2 - sealing gasket; 3 - vacuum pump; 4 — mounting bolt; 5 - vacuum hose
The location of the vacuum pump is shown in the figure 302. Roller 1 is installed only on the turbodiesel engine. When removing or installing the pump, the following operations must be performed:
- remove the air filter and drive belt;
- remove tension roller 1 of the drive belt (if it is installed), why remove the plug and unscrew the Allen bolt;
- unscrew the vacuum hose 5 from the vacuum pump 3. When installing, tighten the union nut to a torque of 30 N·m;
- unscrew the vacuum pump. If necessary, turn the engine crankshaft to release the pump piston. After removing the pump, remove gasket 2 and immediately clean the seat. The gasket should always be replaced. If the pump is being replaced due to bearing failure, check the area around the pump for metal particles;
Installation is carried out in reverse order. Tighten the pump mounting bolt to 9 Nm.
(Publication taken from an online resource mercedesman.ru)