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Weird Transmission Question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Eric78K5, Jan 9, 2001.

  1. Eric78K5

    Eric78K5 1/2 ton status

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    Hey Guys,
    Well, I just finished replacing the water pump on my 78K5 cause the old one was leaking. I also fixed an electrical problem of exposed wires where the starter wires go into the small tube between the headers and frame.
    Well, after refilling all the fluids, the transmission (TH350) doesn't want to shift like it's supposed too. It won't shift into 2nd until around 45 mph, which is high, and once it gets there, it doesn't want to downshift. Now the damn thing worked fine before I changed the pump, so what do ya'll think is going on? It's got me stumped. Thanks for the help, and sorry for the long post.

    Eric78K5
    K5-Because Size Matters!
     
  2. tRustyK5

    tRustyK5 Big meanie Staff Member Super Moderator GMOTM Winner Author

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    Sounds like the vacuum line for the modulator got knocked off, probably when the wires were getting monkeyed with [​IMG]
    Trace the vacuum line back up from the tranny towards the motor and you should find the disconnected culprit.

    Rene

    [​IMG]
     
  3. Emmettology 101

    Emmettology 101 3/4 ton status

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    Ya, I agree with Rene, check for vacuum lines and also, make sure you hooked the wires back up right after fixing them...

    Mike [​IMG]
    See <font color=green>EMMETT</font color=green> -&gt; <A target="_blank" HREF=http://emmett.coloradok5.com>http://emmett.coloradok5.com</A>
     
  4. Eric78K5

    Eric78K5 1/2 ton status

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    Just an update guys. I found the leak, there was a small rubber hose at the back of the manifold that connects to a hard line that was knocked off. Wouldn't have seen it without removing the air cleaner. Put it back on and everything works fine now. Thanks guys!

    Eric78K5
    K5-Because Size Matters!
     
  5. BigJim85

    BigJim85 1/2 ton status

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    Them damned vacuum lines'll get ya every time.

    <font color=red>If it's stupid but works, it isn't stupid.</font color=red>
    [​IMG]
     

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