Vacuum Leak Causing Slipping & Gear Dropping?

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    my transmission last night started acting like its slipping but there’s plenty of fluid and it feels like it dropping into the lower pulling gears. Now I was told a vacuum leak could be responsible but I have no clue does anyone have any advise or have had this happen and if so what kind of a fix and how much?

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    Without a good solid seal, if there is a vacuum leak in your engine then it can cause many, many problems.

    Let’s face it, a your engine needs a vacuum. Indeed, any internal combustion engine produces its own vacuum. It is the way it keeps on running. Look at the construction of the engine and you will see that it is built around its own vacuum. It uses the vacuum to draw fuel and air into the cylinders, as well as drawing exhaust out of the engine and, eventually into the manifold and out the tailpipe. There is no part of the engine that’s not affected by vacuum.

    For example, a vacuum leak can cause rough engine idle because the leak disrupts the engine’s normal vacuum. And, a vacuum leak can cause engine hesitation on acceleration because the leak disrupts the engine’s normal operation, causing it to stumble on acceleration as the engine draws in more air. Believe it or not, this causes the engine to accelerate poorly and it can also cause hard-starting because the fuel-injection system is unbalanced.

    Vacuum is important for proper transmission operation. If normal vacuum isn’t available due to a leak, it can mean improper shifting by an automatic transmission. Further, a vacuum leak can easily disrupt proper shifting because the transmission is unable to find the proper shift points, among other things.

    So, yes a vacuum leak can cause improper transmission operation, as you describe. The leak is usually located somewhere other than the transmission itself. For example, it might be a blown head gasket, where a piece of that gasket weakens and blows out, creating a leak. Or, it might be a pinhole leak in the manifold. A vacuum leak, though it does affect the operation of the tranny, is usually located in the engine and you have to have your mechanic find it.

    How much will it cost to fix? Since it is in the engine and it might involve a couple of hours or more running down the problem and two more fixing it, it could cost up to $1,200, which is, admittedly, an estimate.

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