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928 Views 3 Replies 3 Participants Last post by  RoyH
The delightful engineering marvel vacuum bleed valve on my 1980 300D is sputtering and only dropping from twenty to ten pounds of vacuum - as opposed to the zero vacuum it should be dropping to - causing my transmission to not shift automatically. A new valve costs around $180...

Can this be rebuilt, or must I purchase a new one?
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Check the black line to see if there is any obstruction. It should go to just inside the firewall.
Help! Spooky stuff going on. I checked all the vacuum lines to the bleed valve - no obstructions. To insure the vacuum leak was with the bleed valve only, I disconnected the bleed valve from the system, connected the vacuum line to the transmission modulator to the main vacuum line from the vacuum pump.
I took the car out for a drive, expecting the vacuum system would work for everything and the transmission to not shift. Here's the spooky part. The transmission SHIFTS PERFECTLY with no bleed valve. How can this be? Anyone out there experience same thing or have an explanation?
Sounds like like a spooky blessing.
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