If you are removing the cylinder head from your Mercedes-Benz engine, it is crucial the the cylinder head bolts be replaced when the cylinder head is installed.
Cylinder head bolts are torque-to-yield, meaning that they stretch to ensure proper clamping force. Once these bolts have been torqued, they will not return to their original shape, and will not be able to provide the proper pressure required to keep the cylinder head in place.
If you are removing the cylinder head for any reason, be sure to buy new cylinder head bolts to get the job done correctly.