A defective coolant overflow line may let the expanding coolant vent out of the coolant reservoir tank, decreasing the coolant level. This guide explains replacing a Mercedes Benz GL450 small-diameter coolant line that connects the engine, radiator, and expansion tank.
One of the common symptoms of a defective plastic coolant overflow line is that the coolant level is decreasing, and the engine overheats.
What you will need
- Mercedes-Benz Coolant Expansion Tank Hose
- Flat-head screwdriver
- Park on level ground.
- Shift the car into the Park position, then turn off the engine.
- Let the engine cool down to avoid serious injuries.
- Open the hood.
- Find the coolant overflow line, which stretches from the engine to the radiator and finally to the coolant reservoir.
- Use a flat-head screwdriver to pull each connector’s retaining clip.
- Prepare the new coolant overflow line.
- To connect the coolant overflow line to the radiator connector, align the line with the notch on the radiator side, then press down on the locking clip.
- Align the coolant line to the connector on the reservoir side, push it until it doesn’t move anymore, then push down the locking clip to lock it in place. Note: You may lubricate the connector seal with coolant to minimize the effort in pushing the line.
Repeat the procedure for the engine side.
What does the overflow hose do?
- An overflow hose connects to the radiator below the cap and the reservoir tank to store the coolant overflow.
We hope you find the Mercedes-Benz Coolant Expansion Tank Hose Replacement Guide helpful. Check these troubleshooting and repair guides for more help on your Mercedes-Benz.
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