How to repair the roof of the Mercedes GLK

On the Mercedes GLK, leaks from the roof are almost always due to clogged drains or deformed end caps. Work safely; disconnect the battery if you need to work near the A-pillars where the airbags are located, and protect the upholstery. Open the sun visor and check the perimeter channel: remove leaves and debris with a soft brush, then slowly pour a little water into the corners to locate where the drainage stops. Locate the drain tubes in the front and rear corners and disconnect the terminals only if they are accessible without removing the airbags. To clear the blockage, push a flexible nylon wire from top to bottom with gentle movements; avoid using metal cables that can puncture the tube. Blow compressed air at low pressure while keeping the terminal open, then check that the water flows to the ground. If the end caps of the tubes are constricted or cut, consider replacing them with equivalent parts or remove the constriction that is causing the blockage. Check the roof frame seal: clean it with isopropyl alcohol and protect it with silicone grease; if it is torn or hardened, replace it. Close everything up, wet the frame again with plenty of water, and check for any drips along the pillars and ceiling. If there are micro-leaks from the channel joints, dry them well and apply a thin bead of butyl sealant, compressing it to seal. Once the work is complete, reassemble covers and seals in the correct order and dry any residual water in the cabin to avoid unpleasant odors.