My 300SDL door lock does not lock/unlock 100% all the time.

Front Pass side door fails to lock now and then
Driver door fails to lock now and then
Rear Driver side door fails to unlock now and then

They do not happen all 3 at once, it is kind of random. Probably 1 door at a time. It is unlikely to have 3 sticking actuators?? I suspect it is the pump. Any ideas?

Thanks

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Not MBZ nor A/C trained professional but a die-hard DIY and green engineer. Use the info at your own peril. Picked up 2 Infractions because of disagreements. NOW reversed.

W124 Keyless remote, PM for details. http://www.peachparts.com/shopforum/mercedes-used-parts-sale-wanted/334620-fs-w124-chasis-keyless-remote-%2450-shipped.html

1 X 2006 CDI
1 x 87 300SDL
1 x 87 300D
1 x 87 300TDT wagon
1 x 83 300D
1 x 84 190D ( 5 sp ) - All R134 converted + keyless entry.