I have a leak in the driver's side rear door. Whenever I lock the doors, the leak is not present. But when I UNLOCK the doors, I can hear the air leaking and the pump runs on for atleast 5 seconds before shutting off.

Is this most likely the actuator? I did inspect this problem about 8 months ago, and I was able to wedge something (actually a book of matches!) between the inside of the door frame, and a black rubbery sort of thing (? is this the actuator?) on the inside of the door. It's very hard to see in there to actually see what is loose or leaking.

1. Is it possible that the vacuum line leading to the actuator is loose?

2. Is the black rubber thing inside the door the actuator?

3. How do I inspect in there better? Do I just need to look harder and maybe use a flashlight?

4. Since there is only one vacuum line per door lock (or actuator), then why does it only leak air upon UNLOCKING, but when LOCKING, there is no leak present?

Thanks!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

You need a new actuator, Vacuum locks the system BUT pressure unlocks it. Pressure will push open a hole in the rubber diaphram(actuator). Vacuum will try to pull the rubber back together where the split is in the rubber. That is why you hear the leak on un-unlock & not lock.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Do you think that I would be able to change the actuator myself??
THX

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

I looked in Fastlane and partsshop and couldn't come up with either! Does the actuator have another name? What about a part number? What is the usual cost?
Do you think I'll be able to swap it myself? I am only concerned because of the small amount of room and sight where the actuator is.

THANKS!!

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)

The MB part number is 202-800-11-75 (list is $20), takes about 45-60 minutes to replace.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

THanks for the part # MBDoc!!

Do you guys think I can replace this myself???

__________________
2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)