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In this short 2:32 minute video Kent will show you how he first tests the sunroof drains for blockage and then how he goes about cleaning out any blockage.
DO NOT neglect your W123 hood hinge and firewall corner drains. The problems plugged drains can create arre many and the 123 sedans, coupes and wagons are more prone to front plugged water drains than any other model.
Would you like to watch an inexpensive on demand video that might help you save $1000's? You could spend three or four hours hunting around the internet on different forums and marginal youtube videos and may get the right info - maybe!
Manual sunroofs can have problems too. Just like their electrically operated counterparts, most often they will fail due to lack of lubrication. The number one failure point is a broken T handle. Number two is failure of the roof to close properly due to damaged felt feet and plastic slides.
Groaning, snaping and jammed door check straps are a common problem on the older models (up through 1995). This is primarily due to age and lack of lubrication. Newer models will soon start having similar problems. Rain water getting inside the doors is the big killer.
Malfunctioning and failed power window regulators (mechanisms) are so common on older Mercedes that Kent can almost guarantee if you own one and drive it regularly you will have to fix one at some point.