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About Mack&Cheese

  • Rank
    Engine Started

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  • Location
    West Richland, Washingtion
  • Interests
    Mack Trucks

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  • Model
    RD688S Dump Truck
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  1. Mack&Cheese

    Hard starting after parked for a few days.

    What is the routing of this plastic line. Which side of engine, to where? I may have a similar problem that I'm chasing.
  2. Mack&Cheese

    Dash bulb

    I don't know if this will help, however the bulb that is installed to light up my tachometer is a T1895.
  3. As it turns out the tachometer input is mechanical. Changed out cable with new obtained from Mack and tachometer exhibits the same fault (when running the tachometer won't go below 5-600 rpm and no higher than 1400 rpm. Very sluggish. In my troubleshooting I also found that the incandescent light bulb that is suppose to be plugged into the back of the tachometer was not plugged in, so I suspect that the insides of the tachometer are full of dust and contributing to the sluggish operation, and apparent sticking of movement. Anyone know how to take these apart??
  4. Mack&Cheese

    E7 Specs

    Thanks everyone for the information. Oil and filter change is Monday (Memorial Day) and transmission & differentials are Thursday. I will post my results. My E7 has two (2) spin-on oil filters, and a centrifugal filter.
  5. Thanks Jim, I will start there first. Appreciate the feedback!
  6. Mack&Cheese

    Howdy Everyone

    New to BigMackTrucks, and just purchased a '91 RD688S Dump Truck, E7 460HP, Maxitorque 18 speed, all Mack.
  7. On my '91 Mack RD688S the tachometer doesn't move much at all and usually stays in the 1400 RPM range regardless of engine speed. Where should I look first? Thanks!
  8. Mack&Cheese

    E7 Specs

    New Mack owner here, and needing some information on my truck's capacities. Its a '91 RD688S (Dump Truck), E7 460HP, Maxitorque 18-speed, Mack differentials. I am in need of the amount and types of lubricants used on these components. Where can I find a spec sheet on the engine and transmission that shows these capacities? Thanks in advance for the help!

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