I am troubleshooting a center vent vacuum element issue on a 87 300E.
I get vacuum on the line, but apparently now enough vacuum to open vents
If I bypass the switch-over valve(124 800 0178) and connect the center element to engine vacuum line(found on the switch-over valve inlet), the vents open.
the switch-over value is $105 new and I would hate to replace if the issue is somewhere else.
Mercedes Benz don't stock this item, so I was wondering if this is a common issue or not.
Do they get clogged? what is the average life? Should I buy a used one from salvage yard?