The Dodge strut is the newer form of suspension part that replaced the older style shock absorber. Most of them can be found on front wheel drive cars with an independent front suspension system, but any time a vehicle has an independent suspension they are used. Many times they are referred to as MacPherson struts.
The bottom of the strut on your Dodge is connected to the wheel assembly near the control arm. The top is connected in the center of the wheel well at the strut mount. The function of the Dodge strut is the same as the shock absorber in that it controls the up and downward movement of the wheel so a stable overall ride of the vehicle can be maintained.
The strut on your Dodge is a closed loop hydraulic system and is tested in the same manner as a shock absorber is tested. If there is any hydraulic fluid on the stem of the strut that connects to the wheel well, replacement is warranted. The other test involved depressing the body of the vehicle in one corner. Upon the pressure being released, the body of the vehicle should move up then back to a stable position. If the body continues to move up and down, this suspension part has excessive wear in it and should be replaced.
If one of these suspension parts is leaking it can be the only one that is replaced on your Dodge. If the reason is wear over time, then all of them should be replaced since both of the will have close to the same amount of usage on them. If this suggestion is not followed, the car or truck will be back in the repair shop pretty quickly for the other to be replaced.