Pic. 114. An arrangement of a drive of units on models 280 S and 280 SE. Checking the tension of the drive belt of the coolant pump and generator is carried out at the site "A".
1 - crankshaft,
2 - coolant pump,
3 - generator,
4 - air conditioning compressor,
6 - power steering pump,
7 - compressor.
Pic. 115. The location of the drive belts of the units on the models 350 E and 450 E. Checking the tension of the drive belt of the coolant pump and the power steering pump is carried out in the area "A".
1 - crankshaft,
2 - coolant pump,
3 - generator,
4 - air conditioning compressor,
5 - tension pulley,
6 - power steering pump,
7 - compressor.
After replacing the coolant pump or other units and when replacing the pulleys, the drive belts must be tightened. Checking the tension of the belts should be carried out periodically at regular intervals. A sign of slipping drive belts is the appearance of a clearly audible whistling sound with a sharp increase in engine speed.
The tension of the belts is checked on the belt section between the coolant pump pulley and the generator pulley, for this it is necessary to use a special device. In the absence of a special device, with moderate pressure on the belt, the deflection should be within 10... 15 mm.
For adjusting on an eight-cylinder engine (coolant pump and power steering pump) Loosen the fastening of the three nuts of the reservoir of the hydraulic system of the power steering and use the bolt to tighten the belts and tighten the fastening nuts.
To adjust on a six-cylinder engine, loosen the alternator fastening bolts and nuts, tighten the belts with a bolt, tighten the fastening bolts and nuts. The adjustment method has changed over the period of production of engines of this series, which must be taken into account when adjusting the tension of the drive belts.