[Euro W123]

Ok so I did some research and checked the modulator and the transmission cooler line and they are not leaking. I added some dye in the transmission and it is coming out of the plug to the left of the modulator. Is there a seal on this plug? The epc does not show anything for this plug or what it is. I am guessing there is a piston behind it?

 

[Stretch]

There's a parts break down diagram here that might help.

http://www.ganzeboom.net/images1/ganzeboom/parts/Mercedes/722.3, 722.4.pdf

I don't know which bit you mean though.

 

[Euro W123]

It's the cap that is part of 196 in the diagram.

 

[Rmac58]

Thanks for the link Army, I can't find 196.

 

[Euro W123]

Oops I meant 916