1971 250 / w114 trunk vacuum actuator

[Popeye]

Hi all,

I've recently located the leak on my central locking system (retrofitted): The trunk actuator diaphragms are leaking (on both sides).

I can't find a source for new diaphragms, much less complete actuators. (Diaphragms for sale are slightly larger diameter. I assume these are meant for W123 door actuators.)

1. Are there any sources of replacement diaphragms specific to the trunk actuator? (Original actuator P/N 1078000775)
2. Will a later actuator fit in the earlier car? (P/N 1238000875, https://www.pelicanparts.com/search/?q=1238000875)
3. Can any other actuators be modified to work? (Or use the same size diaphragm?) For example, this one appears simlar: https://www.pelicanparts.com/More_Info/1078002475.htm?pn=107-800-24-75-MBZ&bc=c&SVSVSI=2506 , or this one: https://www.pelicanparts.com/More_Info/0008001175.htm?pn=000-800-11-75-M22&bc=c&SVSVSI=2506

Thanks,
Mike

[meltedpanda]

most of the larger after market actuators will work, the key is fitting them in the location they need to go . Secondly they need to have the "pull" power because the boot actuator , if I recall , has a long lever arm.
unfortunately , until you try one you wont know

[rumb]

https://**************.com/store/1973-1980-vacuum-door-lock-actuator-diaphragm-repair-kit

uncle Kent's website

[Popeye]

Originally Posted by rumb

https://**************.com/store/1973-1980-vacuum-door-lock-actuator-diaphragm-repair-kit

uncle Kent's website

Thank you, and I am very glad those diaphragms are still in production. Unfortunately, they are too big: too wide and too tall for the trunk actuator. I bought a pair hoping they would fix my issue…

I found an actuator on eBay, hopefully it’s tight. If not I’ll experiment with the later actuators and report back.

[Popeye]

I fixed my issue with the eBay actuator. As the part I bought was for the R107 vs. my W114, I had to modify the arm a little: drill a new hole and cut the end of the arm off (with tin snips / easy).

However, while the rubber diaphragms on the "new" part hold a vacuum, they are old. I'm sure I'll revisit this in a few years' time! (In hope of prolonging their lives, I liberally applied Gummipflege.)

[subforry]

I have had some luck "restoring" the diaphragms using a light coat of RTV on the outside.

[Popeye]

Originally Posted by subforry

I have had some luck "restoring" the diaphragms using a light coat of RTV on the outside.

Thanks! I have heard similar with using plasti-dip. I will try one or the other (likely RTV b/c I have it in the house) when the next leak happens (which it will)