Fitting a fan belt in your Mercedes Sprinter 311 is a task you can do with ordinary tools. Install the new belt following the same pattern as you or your technician did with the old. Your new fan belt should go in as soon as you remove the old one. A correctly-working belt draws in air, allowing the engine to cool and saving you from an overheated engine.
Compare the old belt with the new one to make sure it's the same size. Hold both belts in both hands side by side and stretch them to their full length. The belts should be the exact-same size. If not, you'll need to consult an auto parts shop and purchase a belt that will fit your engine.
Open the bonnet of your Sprinter 311 and prop it open. Look to the side of the engine where the previous belt came out. You'll see a series of pulleys which serve as points of connection for the belt.
Starting at the front of the engine, begin stretching the fan belt over each pulley, being careful to hold it tightly to create tension at each point.
You will notice that the belt follows a predetermined and arranged path of slight twists and turns, as if it were a maze. You will disassemble this "maze" starting at the beginning, which is the first connection point at the front of the engine, and continue along this series, removing each point. When it is time to reassemble the new belt, be sure to attach it in the same order as you disassembled the old one.
Tighten the bolts in the series that serve as tension points. This will strengthen the hold of the belt to the engine. The bolts are every point where you disconnect or connect the belt, to serve as reinforcement so that it stays in place.
Close the bonnet of the car and discard the old fan belt.