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Did you guys replace the vacuum modulator with the new updated version?
I would say it's time to check the modulating pressure. How is the car shifting overall? Soft or very hard?
We filled with DEXRON III (SHELL Spirax S3 ATF MD3).
We have not replaced the vacuum modulator. We have just checked it when we rebuild the transmission.
What is this new updated version ?
The car shifts hard when the transmission is cold. Soft then hot (10 minutes later).
Did you guys replace the vacuum modulator with the new updated version?
I have the new one I think it's the new one on GTS 95. Ref. from PET is 126 270 927 9.
My tranny :
The rubber cap ref. 126 987 07 45 is very hard to insert. I can't do it ... I will try again today and I will order new ones (3 $) before to break mine.
I don't want to drive without the rubber cap and to lose the small "T". Reading the MB forums, it seems that the rubber cap is like a seal to avoid vacuum leak.
It just snaps over the top..if I recall. Pictures help
Yes, but it's very hard to push it fully. And it doesn't turn when inserted. I will try again this evening, taking care about the two lugs on the rubber cap.
Yes, but it's very hard to push it fully. And it doesn't turn when inserted. I will try again this evening, taking care about the two lugs on the rubber cap.
The rubber cap..is just a cap..I dont recal having to turn it.
I thought the later transmissions had something to delay upshifts when the transmission fluid is cold to get the engine up to temperature faster and reduce emissions. It may be that yours is working as it should now that you’ve fixed stuff or whatever that component is in the transmission is the problem.
Edit:
Found this on a Mercedes forum:
The transmission upshift delay relay delays the 2 - 3 upshift point in order to heat the catalytic converter faster during cold engine operation. Under certain operating conditions the CIS-E control unit energizes the upshift delay relay via ground. This causes the upshift delay solenoid valve at the transmission to open reducing the governor pressure and raising the upshift point. The 2 - 3 upshift delay point will be raised if:
a. After start up, with the coolant temperature between 60°F and 86°F for a maximum of 80 sec. or up to 31 mph. b. With the coolant temperature between 32°F and 60°F for a short time, depending on the coolant temperature at the time or up to 31 mph.
Below 32°F and above 86°F 2 - 3 upshift delay does not operate.
I thought the later transmissions had something to delay upshifts when the transmission fluid is cold to get the engine up to temperature faster and reduce emissions. It may be that yours is working as it should now that you’ve fixed stuff or whatever that component is in the transmission is the problem.
Edit:
Found this on a Mercedes forum:
The transmission upshift delay relay delays the 2 - 3 upshift point in order to heat the catalytic converter faster during cold engine operation. Under certain operating conditions the CIS-E control unit energizes the upshift delay relay via ground. This causes the upshift delay solenoid valve at the transmission to open reducing the governor pressure and raising the upshift point. The 2 - 3 upshift delay point will be raised if:
a. After start up, with the coolant temperature between 60°F and 86°F for a maximum of 80 sec. or up to 31 mph. b. With the coolant temperature between 32°F and 60°F for a short time, depending on the coolant temperature at the time or up to 31 mph.
Below 32°F and above 86°F 2 - 3 upshift delay does not operate.
07-21-2021 | 05:41 PM
I think it's the new one on GTS 95. Ref. from PET is 126 270 927 9.
