Getting 24 reading when I disconnected at the power brake, still cant find any leak and now the car is shifting like butter. I dont get it, the shifts are as smooth as one can get! I was about to connect a vac line to the modulator and pump it up with a Mity Vac but now its shifting correct? No reason to do that now Any other ideas? Thank you

Your leak was likely at the place where you disconnected to check, and when you reconnected you did it right and eliminated that leak.

Agree.

Ok I have listened to what the techs have said on the forum I purchased a vacuum gauge and hooked it up to the modulator, The vac at 2100 rpm is about 26. When I gun it it drops to 0. In between it fluctuates between the two numbers.

So all in all what does this tell me? Why does the transmission sometimes go through all gears smoothly and other times its abrupt and at times leaves a chirp and wheel spin when it shifts kind of like an old Mustang when in High School with a shift kit.

Its confusing because sometimes when taking it very carefully the transmission at times will shift roughly but usually will shift nice when very easy on the gas.

What you have is an intermittent vacuum leak. It's confusing to you because the gauge shows that the system is working fine. I'm also sure that the shifts were perfectly fine when you checked it with the gauge.

However, under certain conditions............and you will have to ascertain those conditions............a vacuum controlled device is leaking vacuum badly and affecting the shifts.

It's most likely in the climate control system............one vacuum pod could do it if there is no restriction to the system.

Any idea where the climate control pods are?

The w-124 guys can help you with that. There's about five of them and they are hidden in all kinds of different places. You need to test them from the manifold before searching for them............much easier.

For isolating the vacuum to the climate control system look behind the brake booster, you will see a yellow plastic junction of vacuum lines, one line is white (rear headrests), one is green (HVAC) and one is red (vacuum reserve in right fender),

disconnect the green line and plug the open ports - drive around, if its shifting smooth now, your problem is in the HVAC box - the pods are routed through a vacuum/electric servo thing which is beside where the glovebox should be you would need to remove the airbag to access it. To replace pods you would need to remove the dashboard.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

I put a Mityvacon the vacuum modulator and it would not hold pressure. When I drove I kept pumping up the pressure(it only went up to around 15) and the shifting was soft and smooth. A bit flaring but that can be addressed later.

In conclusion I would think the modulator is bad and ordered one from Phil.

Thanks all!

You do not pump it up to upshift. It should upshift fine with no vac. You pump it up for the downshift and for coming to a stop. This is what I did when testing my new tranny.

It will shift so fast that your teeth will rattle............

That makes no sense, the reason why it shifts smooth when Im easy with the gas is because there is vacuum. When I accelerate fast, vacuum goes to zero thus hard neck snapping shifts. When driving since the modulator would not hold vacuum I get pumping the pressure up thus the shift was soft and smooth. Are you guys trying to confuse things?

your test showed 100% that the modulator is leaking. And your concept is spot on for shift smoothness, high vacuum will give slushy shift (less diesel pedal) and no vacuum (diesel pedal to the floor) is supposed to shift hard and quick.

Ideally when installing the modulator you have to put a pressure gauge on a banjo fitting below it and adjust the pressure of a hot transmission with engine running and in transmission in Park, its adjusted with the T handle built into the modulator. If you can note the number on the transmission you can search the correct psi reading on this forum.

Once done you then put the one time use plastic cap on it. This is to ensure you get 100% factory spec setting for best shifts.

__________________
2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

Hopefully my part will come Monday and I can put this all behind me. Does the modulator just pop out or do I need to take the two bolts out that are next to it.

Thanks again to everyone

Nope, you guys have it backwards. The vav is designed to dump the vac when you hit the throttle; the tranny upshifts quite smoothely with no vac (at least mine did - time after time). I know this because I drove mine around the neighborhood with the vac modulator connected to the mityvac. With zero vac my new tranny shifted fine. But the downshift was harsh. Drove it around some more and tried pumping it up with vac (after full upshift) before coming to a stop. It downshifted perfectly with vac from the mityvac as I came to a full stop. I did this many times and it worked the same each time.

Brian - my experience with my new tranny is that it did not upshift too fast without vac. In fact it shifted about right. My experience was driving around with the mityvac hooked to the tranny. The tranny was blocked off from the vav. I reread your explanation about how the vac slows the shift 0.75 sec and that makes sense. However, I did not get anything like the necksnapping shift you mentioned during my trials, not even once. And my shifts varied between WOT and more normal driving. Brian - also I question the WOT idea. When I tested my vac line from the vav to the vac modulator, it dumped the vac all the way down to zero almost instantly at just a touch of the accelerator pedal. (Actually the mityvac has a 5-zero range and it always ended up there - so I could not really tell if it was zero but it was 5 or below).