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Question about Vacuum Pump

Discussion in '1982-Present GM Diesel' started by AzzKicker, Nov 24, 2002.

  1. AzzKicker

    AzzKicker 1/2 ton status

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    I removed the wire that comes from the Vaccum Pump to the VRV. I put in my vaccum guage and at IDLE its not a constant vacum. It jumps from 25inHG to 10 back and forth just side to side real fast. Is this right? Shouldnt it hold constant VACUUM? No wonder my tranny is shifting like shyt.
     
  2. AzzKicker

    AzzKicker 1/2 ton status

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    Ok, I replaced some hoses from vacuum pump to VRV and I still get that the wobbly pressure. BUT when I turn A/C to on, it stablizes. So I drove truck with a/c on so i have stable pressure going to modulator but it still shifts hard. My last thing to replace is the Governor /forums/images/graemlins/frown.gif after that and it still shifts hard I just guess ill have to get used to it.
     
  3. 6.2 man

    6.2 man 1/2 ton status

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    You won't get consistant vacuum at idle . Thats normal !! <font color="blue"> </font color> Rev it up and see what you get , should be consistant !! <font color="blue"> </font color>
     
  4. imiceman44

    imiceman44 1 ton status

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    If it's just the hard shifting, I got used to mine both in the 1ton with a 400, and the van with a 700.
    I think it's the low stall TC that makes it like this.
     

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