Since I am presently going through My locking system right now I though that the Diaphragm/Boot might also be My problem.

However, so far my Door Actuators have a part above the Diaphragm/Boots that is crimped on; the part that the metal Rod attaches to for adjustment.

So before I entertained any thoughts of grinding crimps off I decided to test the Actuator by submerging it in Water and blowing into Tubing connected to it.

From the results of the test the inside Diapharagm appears to be no good and the Boot is OK.
I have searched and so far I find no way to repair the inside Diaphragm and on Ozbenz the guy said ruin the Actuator to get it apart; lots of lock tabs to deal with.

Attached Thumbnails

     

__________________
84 300D, 82 Volvo 244Gl Diesel

My memory is not that good so I am not sure exactly what I did to fix the trunk lock actuator. Now that I think of it (again) I may have used epoxy to fix a leak at the vacuum barb. I tried searching for the post but couldn't find it. What ever I did fixed it and it is still working today.

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

Pic below from a Spanish W123 site.

Looks like you could use the Finger of a Glove.

The other picture showing the split boot was posted by someone from Indonesia. In Indonesia they have the exact same Boot as is ripped for the repair.
The Actuator in the picture is one of the ones that has the Rectangular Black Plastic piceces on the top of it for the Metal Rod.

Not pictured but mine have the whitish clear more cone shaped adjustments on them and it has some sort of Metal Washer inside of the Plastic Cone and the Washer is crimped onto the Shaft. That would make it a lot harder to get off.

Attached Thumbnails

   

__________________
84 300D, 82 Volvo 244Gl Diesel

In My case one of the Door Vacuum Actuators did not pass the test and the Vacuum Valve on the Drivers door did not pass.
I may look inside of the no good actuator to what type of rip the Diaphragm has but I orderd a new one and a Door Valve.

__________________
84 300D, 82 Volvo 244Gl Diesel

My vacuum was being lost on on cold days and intermediately. Traced to one lost line and then found the trunk actuator that test good the first time but then had total failure. Would not hold vacuum at all. Diaphragm and boot appeared to be good. Cleaned out old hard glue around diaphram and used silicone grease to help make the seals, snapped plastic housing back together and notice about 1/32 gap between locking tabs and housing. Used silcone tape to squeeze them together. Hold 25 vac and drops to 15 after 12 hours.

What type of glue to hold the boot to the actuator shaft?

The housing was still leaking. Upon closer examination, the plastic had a dent on the sealing area that was mended by what looks like epoxy, but not fully built up to level and over level on the inside. May epoxy or plastic welding. Anybody know that the housing is (pvc, pp, abs plastic)?

For US residents, EPCnet online has the data card information for free. Outside the US there is a charge. http://epc.startekinfo.com/
Requires JAVA 6 and will not work with JAVA 7.

anyone know if the diaphragms are available for the old style (first generation W123) actuators?

The housing may also be glued together. I used a metal putty knife to break the glue apart. The putty knife also holds 2 of the tabs apart. Then repeat on the other side. My housing had a defect that was repair at the factory with glue (epoxy?) but not perfectly. It also looked as if there was dried grease (a German grease the is yellowish in color . I used it 30 years ago, but forgot the name. It was $$$). The diaphragm can likely be repaired with Aquaseal or UV rubber repair glue.

try http://**************.com/search/store?filter0=actuator&filter1=**ALL**&filter2=1

I finally did a good fix. Used Permatex flowable silicone 81730 to put a bead and let set for 15 minutes stricken before setting the bellow on it. Used 2 small weights to keep them in place and to allow it to dry for 60 minutes. Then put another bead on the other plastic half, allowed to set for 15 minutes and snapped halves together. Failed to achieve vacuum when connected to both nipples. Had to press halves together then used 5 in Hg vac to hold halves together. Plastic weld the half's together every 5 to 7 mm. Added more flowable silicone to the seam for extra measured. After 12 hours silicone still had some mushiness with the residual silicone in the Permatex nozzle. After 24 hours all was solid. Tested by blowing/bubble test (don't use pump). vacuum hold tested for 8 hours and all is good.

If I were do it over, I would use regular RTV silicone for making the gaskets. then pull the vacuum to hold the halves together for plastic welding.

Or if only leaking through the sides and still factory glued or welded together, I would just try the flowable silicone along all of the seams, pull light vacuum to get the silicone between the plastic and rubber bellow, squeeze to hold 5 in Hg vacuum, wipe off excess silicone, plastic weld the halves, and then more flowable silicone and release the vacuum for at least 24 hour of curing.

I just replaced my diaphragms on my old style actuator. I made a 'how-to' on it here. These were bought from M*rcedessource

http://www.peachparts.com/shopforum/vintage-mercedes/336342-old-style-vacuum-door-lock-actuator-repair.html

__________________
1985 300d smoke silver/red int. (204k) <--Sadie the 80's Mercedes from Hades!
1985 300TD 587 cabernet red/155 Creme (143k)
2007 Ford Expedition EL (54k)

"Seems to me you bought a hobby... not a car" - My dad.

Thanks for the link.
BTW: My truck has the yellow with red strip as the lock. The green stip line is unlock -- opposite of the typical diagrams. The red striped line is on the oposite side of the actuator rod on the trunk and the passanger doors' actuator. The external boot side (unlock) leaks a little bit more than the lock side (<1 mHg/min verses 2 mHg/min boot side). This make sense for holding the vacuum when the car is locked. The new style fuel door lock is the opposite of the old style fuel door lock and likely why MB has two tees at the fuel door lines.

bosch 3 340 522 025

Anybody know where to buy these above shown seal numbers for the door lock actuator?

__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.