1998 Suburban-coolant leak-maybe WP maybe lower radiator hose?

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by phoebeisis, Jan 11, 2014.

  1. phoebeisis

    phoebeisis Epic Member 5+ Years 1000 Posts


    My 1998 Suburban-224,600 miles-last 6 years 30,000 mine.
    It has a coolant leak-maybe more than one.

    I have been smelling coolant when I get out-or when I pop the hood for at least 6 months

    Now when I crawl under-I see coolant- at the lowest point on the lower radiator hose-
    and on a smaller hose-trans cooler maybe-under it.
    Looking upward-I see a damp stain-where the hose meets the water pump-

    Best guess is it leaking where that hose clamp has maybe cut crushed it?
    Or is the water pump leaking -changed maybe 3-4 years ago(Autozone $150 piece of junk rebuilt)

    Is there a weep hole in that general area-that leaks when the water pump is failing?

    Oh-I have put dye in it-months ago-found a cracked heater hose T-FITTING-this is the black light dye-yeah have a black light-not really as useful as I hoped

    I also see some greasy dampness far right-under the radiator-under what from memory I think is the tran cooler fitting or maybe the oil cooler fitting.It 'always" oozed a bit

    What do you think?Most likely leak place-for a very slow leak-that has suddenly increased-near Water pump and lower hose junction-
    hose could be pretty old-7 years or more-feels OK but
    Will a failing water pump put 1 pint of more out the weep hole-20 miles?-After leaking probably no more than 1 ounce per 20 miles for many many months
    PS- yesterday-from reservoir-it seemed to leak maybe 1 pint for 21 miles-so leak has INCREASED a lot-obviously I check it daily
  2. MrShorty

    MrShorty Epic Member 5+ Years 1000 Posts

    The common coolant leaks that I know of:

    1) Intake manifold. When my intake manifold was leaking, it was a slow leak at the front of the engine. I can't remember if it dripped off of the radiator hose or off the engine, but it was definitely the front.
    2) Water pump. I'm almost certain there was a weep hole in my water pump, and that was where it started leaking from.
    3) "quick connect" heater hose connector coming off of the intake manifold -- usually starts leaking after fixing the intake manifold gasket because it doesn't seal back up cleanly.

    So, water pump is certainly a possibility. Before I bought the new water pump, I'd probably go to autozone and borrow the cooling system pressure tester, pressure up the cooling system while cold, and see if you can verify that it is leaking from the weep hole and not from the intake manifold higher up.
  3. phoebeisis

    phoebeisis Epic Member 5+ Years 1000 Posts

    Mr Shorty
    Gotta better look last night-with the black light
    A bit of coolant pooled in a place than sure makes me worry about the intake manifold gaskets

    I really don't want that to be the answer, because I had a jackleg mechanic replace them-3-years ago-unfortunately he partially stripped the hole that holds the harmonic balancer onto the crank- and at least three others-and I didn't check the fasteners that actually hold the intakes on-safe bet some of them are threaded.

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