AT Modulator Valve Question

[Mrbiskit]

I have a 84 Mercedes 300D Turbo. I now know (because of all the great information here) that I have a bad or leaky modulator valve, I went to purchase one from this website, but I don't know if I need the .315 or the .422 version. Could anyone tell me which one I need or the way to figure out which one I need?

I also have a similiar question for the vacuum dashpot, I am not sure which version I need and I can't seem to get a part number or model that corresponds to the information listed in the dashpot description on this website.....I really appreciate everyone here and any help is greatly appreciated. Thanks BH

[rhodes2010]

Not the answer you wanted but.....

I thought I needed the whole modulator for my 1983 and it turned
out to be only the little tiny cap, cost about 2.50.

Do a vacuum test on the modulator only, then pop off the rubber cap and
maybe just use your thumb to cover hole and see if you can get a no-leak
test.

If so you probably only need the cap.

Now, as to which modulator, in case you are still going to end up there.
What serial number is your car ?

I am not exactly sure, but this may help determine which modulator.

[Mrbiskit]

I really appreciate your help. I don't have a means to test the modulator right now, I do know that fluid is leaking out of the cap. First to second is tight and quick and second to third is fairly smooth. 3-4 is very notchy and the car tends to downshift into first at twenty miles an hour with a clunk. I figured out some vacuum problems about a week ago and the behavior is consistent. I guess I am trying to say the shifting is a little smoother but the gears are shifting in the above manner just not as bad as they used to be...Based on this slight improvement but no serious variation, I am assuming the regulator is bad.
I would probably just prefer to throw the kitchen sink at it if you know what I mean, I prefer to mess with things only once.

Thanks again RHODES, I appreciate you sharing your knowledge with me.
BH