Steering and Suspension

Page 44

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Volvo Bus Service and Maintenance Manual

 Level control ("LEVCONTR")
89 Check the function of the working cylinders when raising the level. Where such a system is installed, also check the level lowering function.
 Bus with leaf springs
90 Check the springs, spring shackles and U-bolts.

Level control system

Available as optional equipment is a level control system for both raising and lowering the bus's ground clearance by approx. 80 mm. There is also an alternative with only level raising. Both raising and lowering the normal driving position level is activated by a common switch on the dashboard, see further Service Manuals, Section 3-37 and Section 7.

Check that all working cylinders are readjusted to extend approx. 80 mm when raising the level.

Check to make sure the air bellows are not fully discharged when lowering the level. The relief valve in the discharge for the solenoid valves should close at a pressure of 120-160 kPa.

Solenoid valve level raising
Solenoid valve level raising ("6003")
Suspension bellow height
Solenoid valve level lowering, rear axle ("6004B")

Bus with leaf springs

With a jemmy bar check the spring shackles and spring attachments for wear. Max. permitted spring bolt play is 3 mm.

Broken or displaced spring leaves may be due to a broken centre bolt.

If suspension movement causes marks between the spring assembly and the contact surface on the front/rear axle, check-tighten the U-bolts.

Spring suspension bolt play check

The front and rear wheels must be on a level surface when replacing rubber bushings in the leaf springs or when tightening up loose spring bolts. This will avoid a stress which could subsequently cause vulcanization between sleeve and bushing to break off. The tightening torque for the spring bolts is 390 Nm (39 kgf m).

Spring suspension bolt tightening