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  1. #1

    Default First Suburban ~ Have Some Underhood Questions on my '99

    I recently picked up a 99 Suburban, 197K miles, barely broken in...I have a couple underhood questions:
    There is what appears to be a factory installed secondary battery tray, and there are two positvie leads off of the battery. what is puprpose of this second tray?

    Also on my radiator, just below the filler neck, there is a roughly half inch nipple that is capped off, any idea of the purpose of this additional fitting?

  2. #2

    Default Pics of radiator outlet

    This is the outlet on my radiator I am not sure of. Also, my truck is a 1/2 ton, with a 5.7L .
    Attached Thumbnails Attached Thumbnails WP_000128.jpg   WP_000127.jpg  

  3. #3


    Hmmm, interesting. Maybe an aftermarket/replacement radiator?? Mine is stock (1998) and doesn't have the capped off nipple so I'm not sure...

  4. #4


    I'm reasonably sure (my Suburban is out and about right now) that the unattached fitting is for an optional engine oil cooler. Replacement radiators tend to have both engine and transmission oil coolers (don't need to stock as many radiators). So, as noted, the radiator has been replaced at some time, and the engine oil cooler was not used.
    '98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
    '92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
    "My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World

  5. #5


    its an aftermarket radiator that was produced to fit more than one style of vehicle so that extra nipple was for a vehicle that would have used it. its a place to watch for coolant leaks, i have seen the rubber cap crack and then burst after time and you loose a bunch of coolant.

    2003 Z71 Silverado LS
    Access roll up cover
    Bed Rails
    Billet Grill insert
    Bed Rug
    CB with PA system
    Waiting to be installed
    Two 8in RF HX2 punch( would have 12s but they got stolen)

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