C4-vacuum diaphram
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C4-vacuum diaphram
Ok, guys, my early c-4 holds first entirely too long under full throttle, and from my reasearch on the web it looks to me tobe the vaccuum diaphram that moves the throttle valve. my question is, how hard is it to replace this little beastie, and how much will it cost. from past experience i'm guessing it unscrews, and probably costs 30 bucks. what do you think? from what i can tell, it's sticking and not letting go when the engine vaccum lessens, and it's taking too long to let go. thanks in advance.
Dave
Dave
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C4-vacuum diaphram
it turns out that the "vacuum diaphragm" is also called the transmission Modulator, or vacuum modulator, does any know how long it takes to replace the "Modulator" or if any special tools are required?
thanks
dave
thanks
dave
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From: Crossroads of America-Ind
C4-vacuum diaphram
Dave, it just takes a few minutes. There's only one bolt holding it in. When you pull it you'll get fluid out of the hole and there's a small pin inside. Make SURE the pin goes back where it was or no worky!
Have a drip pan ready for the fluid and you can slide one out and the other in real quick. Course you could go ahead and change fluid then to if you need to. Good luck,
Have a drip pan ready for the fluid and you can slide one out and the other in real quick. Course you could go ahead and change fluid then to if you need to. Good luck,
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From: SE PA
C4-vacuum diaphram
If it's like the C-6, then all you need is a 7/16" or 1/2" wrench or socket. My C-6 has a steel "keeper", a piece of flat stock with a fork on the end to hold the modulator in place. Make sure you don't have a vacuum line off or broken at the tranny or the engine though, this will cause the same problem. It's not unusual to see a little "oil" smoke when the diaphram gives up, it sucks it from the tranny into the intake.
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C4-vacuum diaphram
Yeah, the swap wasn't hard, but it is IMPORTANT to get the one for the right year, because apparently they are made for different vaccums on different transmissions. The problem was that the old owner had a) painted the bottom of the tranny black, b) not transfer year info to ME. so i guessed at a year, then switched it out, tried it and no-go, so i took the old one in and found just a little bitty spot of the yellow band,that should do the trick. Thanks for the info.
dave
dave
