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1990 GMC Jimmy radiator.

Discussion in 'The Garage' started by hawkeye649, Sep 23, 2004.

  1. hawkeye649

    hawkeye649 1/2 ton status

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    Hi!
    I have a 1990 GMC F/S Jimmy w/AC and a 350 TBI engine.

    The Story: /forums/images/graemlins/doah.gif
    There is a "small" leak along one of the seams of my 34"x21"x2" radiator. I let the truck compltely cool down, drained the fluid (I was flushing anyways) and applied JB weld bond. I let it cure over night, (about 16 hours at least, I slept in on the weekend). Did my flush, and everything seemed alright.
    Well it's still leaking, so now I have a purdy black radiator covered by nasty grey stuff that has a green tinge to it.
    I have been looking at the radiator and thinking it looks pretty easy to pull.

    The thought: /forums/images/graemlins/thinking.gif
    Thinking of either chipping away the JB & brazing it (not super feasable, can't find my torch...) or putting in a new radiator.

    The questions: /forums/images/graemlins/confused.gif
    Do I have a 1, 2, 3, 4 core radiator?
    Should I just replace it with what I've got, or would a "more core" radiator help? I don't know what the difference is?
    Do I need to have the fan shroud to keep it cool? It's cracked and the fan hits it if I wrack the frame. Engines also look cooler without them. /forums/images/graemlins/whistling.gif
    Thanks for all the helps and abuse. /forums/images/graemlins/ears.gif
     
  2. hawkeye649

    hawkeye649 1/2 ton status

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  3. Jonny-K5

    Jonny-K5 1/2 ton status

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    first of all, you HAVE to have a shroud. otherwise the fan will not pull air thru the radiator when at low speeds, and your trucks will most likely overheat at stoplights.

    if its stock, you have a 3 core. thats what they come with from the factory.
    i had a 4 core custom built by a radiator shop. couple years later it started leaking at one of the end caps. i put in a new stock 3 core and it cools just the same. i dont think its worth getting a 4 core if the rest of your cooling system is in good condition. unless maybe you tow heavy loads in the middle of the desert.

    i would either take it in to a shop and have them repair it.they will probly suggest you rod it out if its the original. by then your probly close to what a new one costs. mine was about 175.

    its really easy to remove it for repair. if its the original, i'd just buy a new one and replace it myself.
     
  4. diesel4me

    diesel4me 1 ton status Premium Member

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    A new radiator is always best,you may be able to solder it ( I dont think you could braze it--brass melts at a higher temp than your radiator will!)after removing the J-B Weld(heat from a propane torch might help pop it off,but be careful not to un-solder the tank or tubes in the process).A 50/50 solder with flux usually works best.I have had good results with powdered ALUM A SEAL stop leak too,more than solder, in a few cases I had to solder AND use the stopleak.
    You have to count the rows in your radiator to see which one you have,usually you can see how many rows it has by looking at the tanks,or in the radiator cap hole.Bigger is always better in the cooling department,and you should keep the shroud--if you dont the first time you get stuck in traffic you'll be cursing,and hoping you dont overheat or blow a head gasket--I know someone will say they took theirs off and had no problems,but GM put one on for a reason,it IS nessasary in my opinion,especially when standing still or going slow.
    A bigger radiator may require the matching brackets to install it--but going by the dimensions you listed I'm guessing its already one of the biggest ones available,if you have A/C,or a heavy duty cooling system its probably a 3 or 4 core. /forums/images/graemlins/crazy.gif
     
  5. rjfguitar

    rjfguitar 3/4 ton status GMOTM Winner

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    I bet it's a 3 core. I don't think a 4 core was available. They are easy to take out, there are two brackets at the top, remove the shroud bolts, slide the shroud towards the motor, remove your hoses,tranny lines, and thats it IIRC. I would take it to a rad shop because chances they can fix it and rod it out for you and get you out for less than $80 or so, they will tell you if it's too rotten to reuse.
    IF you do deside to purchase a new one I would say that a replacement 3 core should be plenty. You could go with a 4 core but they cost more and I doubt your engine would ever need the extra cooling power. Plus you have to mess with getting new brackets for a 4 core.
     

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