Rear damper

Fig 1: Illustration For Steps 1-9

Courtesy of SAAB-SCANIA OF AMERICA, INC.

Rear damper 

1. Piston rod seal
2. Piston rod
3. Inner tube (working cylinder)
4. Outer tube
5. Dust excluder
6. Valve
7. Fluid
8. Bottom valve
9. Gas

The rear dampers are of the double-acting, twin-tube, gas-filled type.

The gas pressure is used to maintain pressure on the damper fluid. This reduces the foaming tendencies of the fluid and also the formation of air bubbles that could result in noisy operation of the damper.