I hae a 1999 s320, think i have problem with vacum system. The trunk closing latch mechanisim retracts than it comes out again. Also notice that the lumbar suports on both seats start pumping air by themselves. I think the system leaks than it refills. Anyone had any problems like this.

thanks.

 

yup i have seen it quite a few times you need to check your system for leaks. with a vacuum / pressure guage

 

The locking pump under the pass rear seat handles the lumbars (it pressurizes a reservoir) and replenish it. The pump drives the handle , the locks, the manual headrest, and auxilliary vacuum for the HVAV. It has timing cicuits and safeties.
Pressure to lock, vacuum to unlock, The handle should retract, it appears the pump suts off prematurely before the handle is in. The best tool is called a MIghty -Vac lets you draw a vacuum and and look at the guage to see if it leaks down. Plastic $30/aluminum$50