Trans vacuum modulator
#1
Instructor
Thread Starter
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How do you guys adjust a new modulator. I replaced a leaking vacuum modulator and now I need to adjust it . I replaced it because it was leaking trans oil. This is a photo of the old one. The new one is different. It has the black rubber cap on it. Thanks, Doug.
#2
Nordschleife Master
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Carefully remove the black rubber cap - don't violate as it is needed to hold vacuum. There is a small 'T' key that is used to turn CW or CCWise, and fit back in the notches. See pg 3.3/3 on the link.
https://brandon314.files.wordpress.c...ull-manual.pdf
https://brandon314.files.wordpress.c...ull-manual.pdf
Last edited by MainePorsche; 10-19-2015 at 11:53 AM. Reason: page correction
#4
Nordschleife Master
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'...The WSM also suggests driving at 140 kmh (or 50 kmh if 140 is going to be tough). After talking with a bunch of MB techs, turns out none of them do this - all check pressures at idle and stationary. So that's what I did.'
Would be curious to hear what Greg Brown would say about measuring the modulating pressure while not under load.
Would be curious to hear what Greg Brown would say about measuring the modulating pressure while not under load.
#6
Nordschleife Master
#7
Instructor
Thread Starter
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Thanks everyone. I've been trying to stop the Trans leaks for sometime and now it appears (I hope ) that this just might be final fix. I will get the proper adapter to mate the hose to the port tomorrow and give the adjusting a go!
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#9
Former Vendor
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'...The WSM also suggests driving at 140 kmh (or 50 kmh if 140 is going to be tough). After talking with a bunch of MB techs, turns out none of them do this - all check pressures at idle and stationary. So that's what I did.'
Would be curious to hear what Greg Brown would say about measuring the modulating pressure while not under load.
Would be curious to hear what Greg Brown would say about measuring the modulating pressure while not under load.
However, since the adjustment is just to get things close and then adjust to personal preference, idle is probably close enough.
#10
Nordschleife Master
#12
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I bought this kit. Worked very well. It contains all you need.
https://mercedessource.com/store/61x...ssure-test-kit
https://mercedessource.com/store/61x...ssure-test-kit
#14
Instructor
Thread Starter
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Well ,I hoped to get a fitting to connect the gauge to the port ... No luck. Ihoe,I'll be ordering the kit you suggested. Thanks for the heads up on that.
#15
Instructor
Thread Starter
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Two questions..... the new vacuum modulator is different than the one in the photo in the first post .It has the black rubber cap. So, does the plunger that worked for the old modulator work for the new one? The plunger fits in a "hole" in the modulator. The new modulator has a flat piece of metal and no depression.
The other question ... what values do I set the modulator? Is it 4.2 bars?
The other question ... what values do I set the modulator? Is it 4.2 bars?