W140 S500 both rear door unable to open
 

I have a 1997 W140 S500 and has already 275,000 kilometers, both front door locks work properly but rear doors are unable to open from inside or outside and door actuators are goes up and down those locking pins. I don't think the vacuum pump is the problem and seems the actuator are moving when the fob remotely pressed. please help what to do.

When the locking pins do go up are you able to use either the inside or outside handles to open the door

You will have nightmares on fixing this problem. I know I had the same problem on my 97 S320 left rear door. The problem is that there is a short roller link that get frozen in place due to lack of use or corrosion. The roller link is spring loaded with a weak spring. As long as it is in the lock position there isn't much you can do except butcher the door panels to get to release it if pounding on the door with a mallet doesn't free it up. It is impossible to release the short roller link without removing the door panel. I can send you more pictures but here are two that show the roller link that causes the problem


https://cimg9.ibsrv.net/gimg/www.mbw...81f5745abf.jpg
https://cimg8.ibsrv.net/gimg/www.mbw...8370837c6e.jpg

You vacuum pump which is located under the rear passenger side seat, might needs to be replaced. This vacuum pump controls every lock on the car. It's a black book. YouTube it.

I doubt its his vacuum pump because he says that both inside manual door pulls go up and down when actuated. The problem is probably like I posted.
Dan

Here is a video of the door lock mechanism and why it does work even if the manual inside and outside door handle work and the hand pulls up and down by pneumatics.