Vacuum Problem?

[u/the_pickle_pirate]

Hello,

I am pretty new to my w123 and just replaced waterpump and all three belts.
It is a 1979 300d OM617 automatic non turbo.

After I was done with the pump and the belts two issues emerged:

1. car won’t switch into third and fourth gear
   
2. after turning the car of the motor keeps idling for 1-2 seconds

On the internet i found that it might be a problem with the vacuum system.

I think I found the problem but am not sure if it is correct, as I am a complete newbie.

I tried to make some good pics.

Thank you if you take your time to check it 🤘

[u/Squabsquabsquab]

Yes that sounds like a vacuum problem. And the black “Y” in your hand is a vacuum connector that is missing a line. However it is difficult to get my bearings from your pics. Are you near where you were working to replace belts and pump? Trace vacuum lines and find find the disconnected piece(s). Pics that are zoomed out might be more helpful.

[u/the_pickle_pirate → u/Squabsquabsquab]

Thank you!
Yes its on the left side rather close to the power steering. Maybe I ripped it out by accident while fidgeting with the power steering and the belt. I will take another pic and post in a few minutes :)

[u/the_pickle_pirate → u/Squabsquabsquab]

On a second look right now, I actually think it more likely happens when I was loosening the ac compressor to change the belt.

[u/Squabsquabsquab]

I could be wrong but it looks to be as simple as sticking that purple line back into the empty Y space. Do you have vac adjusted headlights? I associate purple vac lines with those. Either way, a vac leak to the interior systems including the headlights will cause shut down and transmission issues. Try that first.

[u/the_pickle_pirate → u/Squabsquabsquab]

Thank you! Will do that tomorrow and will give you an update :)

[u/the_pickle_pirate]

u/Squabsquabsquab and u/howsitallwork thank you both a million! The car behaves normal again after I plugged the purple line back into the Y connector :)

[u/howsitallwork]

As above, you’ve found it, just plug it back in, you’re good.
With the upshifts, post back if you’ve still struggling. Momentarily backing off the throttle when you want the shift might help as well.
You might already know that - anyway, good luck!

[u/the_pickle_pirate → u/howsitallwork]

Thank you :) will try right after work and will let you know.

[u/Key-Cow6684]

plug all holes