Using muriatic acid to refresh the cooling capacity of your radiator?

Discussion in '40- & 55-Series Tech' started by ERICH, Feb 23, 2004.

  1. ERICH

    ERICH

    Messages:
    190
    Hello
    Almost a year ago I posted a problem I was having with my FJ60 running too hot and after replacing EVERYTHING but the radiator someone suggested taking it out and putting muriatic acid in to really clean it out. Normally I would replace with new but, I have two trucks like this now and money is a bit of an issue right now, so I am wondering if anyone has done this before? I bought the stuff at the hardware store and after reading all the warnings I would like to know what sort of concentration to use. The bottle I got is 31 percent, and says that it is used to etch concrete, for pool water,etc. Anyone out there know anything about this?
    Thanks in advance for input.
    ERIC
  2. Rice

    Rice SILVER Star

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    1,077
    Location:
    GSO NC
    Have never tried that. Whenever needing a serious radiator cleaning I've taken to radiator shop that boils them out for about $35. Price has always sounded good to me and they've always come back looking very nice.
  3. Degnol

    Degnol SILVER Star

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    8,123
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    Kansastitty
    I've cleaned several heater cores, but I used CLR, a combo of hydrochloric and phosphoric. Straight Muriatic is pretty stout stuff. You'd want to disconnect the radiator from the cooling system anyway, so like the previous post, I'd take it to a radiator shop. You might try some of that proprietary radiator/cooling system flush, some of which needs to be neutralized. That'd be easiest, cheapest.
    Ed :)
  4. i dont know much about concentration %, but i have used muriatic acid from home depot intended for pools, maybe the same or similar to what you have.
    i tried this as a last effort before a re-core so i was willing to try it out, nothing to lose.
    this is the typical procedure,,,,take the rad. out of the rig and duct tape the hose openings shut, pour the whole gallon in full strength and replace the cap, lay the thing down flat for an hour, then swoosh it around and lay it on the other side for an hour. do a good rinse and re-install.
    when i did this is worked pretty good, it wasnt like new but it did work. didnt seem to cause undo damage to the rad and i had no leaks for the next year or so i ran it. eventually i did re-core the rad.
  5. Advent Horizon

    Advent Horizon

    Messages:
    38
    I once did this to my heater core. It cleaned it out, but it appears that some of the gunk in there was plugging a hole...Ended up spewing coolant all over the floor 2 days before I had to drive 400 miles.
  6. Kief

    Kief

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    4,262
    Location:
    Southwest Oregon
    Wear gloves and goggles, don't do this operation on anything that you care about.. concrete, lawn etc.
    Use it straight, if it eats a hole through then you get to buy a radiator, which you would have had to anyways cuz the hole was just plugged with crud. There was an article in TT once about this. I look up the details but I am too lazy.The duct tape holes will work ok, better to use plumbing plugs or caps which can be reused when you do a pressure test vs. putting in your cruiser and finding out it is bad. Neutralize with baking soda and water mixture after hosing it out. Recover all acid and dispose of properly of course. Oh yeah, if after you do this your favorite jeans have a bunch of holes in them you splashed acid on them.

    Good Luck.
  7. HI^C

    HI^C

    Messages:
    1,221
    search around got a shop here does free boil and test, Then give free estimate on repairs. taken maybe 10 radiators to him in 5 yrs, always honest and fast. had many that were just a boil and test then me pickup in the same day when possible. Can not beat service like that.
  8. tewlman

    tewlman

    Messages:
    331
    i'd take it to the radiator shop if it was mine. 35 bucks sounds about right for a hot bath and you dont have to worry about chemical burns :)
  9. SteveLCetc

    SteveLCetc

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    2,339
    Location:
    Ground Control
    Muriatic Acid is Hydrochloric Acid. You don't want to put it in your engine unless you don't care how long the engine lasts...
  10. toddslater

    toddslater SILVER Star

    Messages:
    1,494
    Steve is right it is HCL....take it back to wherein you bought it...pull the rad and spend $35.
  11. redrock

    redrock

    Messages:
    62
    Muriatic acid is the commercial trade name of a relatively weak hydrogen chloride mixture (about 30%) which by any other name is still just hydrochloric acid. It is also the same active ingredient that the radiator shops use to "boil" radiators.

    For about $1 worth of solution, you can clean it as well as any radiator shop, especially since you will have to remove it anyway, unless you want to pay a highly trained radiator "technician" and add that to the bill.

    The radiator flush article in Toyota Trails, as referenced above, was written by Mark Whatley and is on page 25 of the July/August 1998 issue. To summarize:
    ..remove the radiator or heater core
    ..empty the remaining coolant
    ..position the openings facing up and fill with muriatic acid. Let it sit for 10 - 15 minutes--no more
    ..flush with clean water, and repeat the procedure.
    ..flush thoroughly with clean water, and re-install

    Three things: this procedure is designed for old-fashioned, brass radiators. Never use on the new-style aluminum/plastic coolers. Do not use the acid wash with the radiator in the vehicle--it will inevitably spill on surrounding parts and damage them. Finally, don't spill this mess on your driveway. It will eat concrete.

    If this won't clean it, it will need to be recored or replaced. I have done this to several old heater cores and have had very good results.

  12. ranger

    ranger

    Messages:
    1,147
    Location:
    Idaho
    [quote author=redrock link=board=1;threadid=11939;start=msg110486#msg110486 date=1077756468]
    Muriatic acid is the commercial trade name of a relatively weak hydrogen chloride mixture (about 30%) which by any other name is still just hydrochloric acid. It is also the same active ingredient that the radiator shops use to "boil" radiators.

    For about $1 worth of solution, you can clean it as well as any radiator shop, especially since you will have to remove it anyway, unless you want to pay a highly trained radiator "technician" and add that to the bill.

    The radiator flush article in Toyota Trails, as referenced above, was written by Mark Whatley and is on page 25 of the July/August 1998 issue. To summarize:
    ..remove the radiator or heater core
    ..empty the remaining coolant
    ..position the openings facing up and fill with muriatic acid. Let it sit for 10 - 15 minutes--no more
    ..flush with clean water, and repeat the procedure.
    ..flush thoroughly with clean water, and re-install

    Three things: this procedure is designed for old-fashioned, brass radiators. Never use on the new-style aluminum/plastic coolers. Do not use the acid wash with the radiator in the vehicle--it will inevitably spill on surrounding parts and damage them. Finally, don't spill this mess on your driveway. It will eat concrete.

    If this won't clean it, it will need to be recored or replaced. I have done this to several old heater cores and have had very good results.
    [/quote]


    Exactly. I have done this procedure to two radiators and heater cores. Worked like a champ. Just make sure you neutralize the acid, I can't remeber if it was boric acid of baking soda that works. It will have the correct agent to neutalize on the muratic acid bottle.
    I spilled some on my concrete driveway and all it did was etch it. Almost looked like I spilled bleach on it.
    Don't get it on you skin or clothes, don't breath the fumes.
    It cost $7 for the bottle of acid. The rad shop wanted $50 to rod it out!
  13. cavsfj40

    cavsfj40

    Messages:
    194
    muriatic is pretty weak, and if you get it on you, rinse with water and there will be no harm. It is not vinegar weak by any means so wear some friggin splash goggles. oh, and my dad uses it to clean the driveway every few years so i wouldnt worry about it ruining it since he has been doing it for 20 years with no ill effects. acid can go in the sink as long as it is diluted beforehand also.
  14. sherwood

    sherwood

    Messages:
    176
    Location:
    Charlotte, NC
    Chemistry for modern living.

    Georgie was a chemists son,
    Georgie is no more,
    What he thought was H2O,
    Was H2SO4

    More battery related, maybe.... but pertains to acids and alkalyes.

    I've always used baking soda when working around the battery compartment. Used to do a lot of work on electric wheel chairs with 2 batteries. 'Would sometimes see 4 or 5 a day.

    Mix three or four tablespoon's full of good ol' Arm & Hammer into a cup of water. Stir well. Pour or paint all over your battery connections and tray. Be very careful NOT to get any on top of the battery where it could migrate into the cells. Some batteries do not have lips around the cells to prevent this. I usually dip the ends of the wires with the terminal connectors into the solution and let them sit a while. Toothbrush helps with thick build-ups.

    I'm sure it would help neutralize the radiator situation also.

    On a safety note... in spite of what some folks say.... I have personally seen two batteries explode like hand grenades. One guy was jumping a battery in a car in front of a restaurant. Don't know what he did to fawk up. It blew up and acid went all over his face and in his eyes. The cook ran out with a gallon of milk and poured it all over the guys face and held his eyelids open and flushed them with the milk. Doctor said it saved his vision from certain ruin. Milk could save your bacon.

    John
  15. theo

    theo

    Messages:
    1,432
    Whether or not you use muriatic, you should know it is NOT a weak acid! The strongest commonly available concentration of HCl (hydrochloric acid) is 36%. So treat it as if it could harm you, because it can.

    Sidenote: muriatic is simply a common name given to HCl back in the late 1700s, before the element chlorine had been discovered.
  16. ERICH

    ERICH

    Messages:
    190
    REDROCK
    Thanks for hitting the mark that I was looking for, I knew the answer was out there. I like do anything and everything I can myself, I have five FJ60's so it nice to know this. I have two back up radiators that don't cool like they should, and I would like to be able to refresh them so to speak.
    Redrock you rock, thanks.
    ERICH
  17. Splangy

    Splangy SILVER Star

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    4,264
    Location:
    New Hampshire
    Nobody suggested that he should run it with HCL in still in the rad!
  18. 22rsolid

    22rsolid

    Messages:
    5
    I'm tired of buying Prestone products that don't work.

    I have a gummed up radiator. I hope the water jackets aren't
    too gummed up.

    1. I've used Prestone cleaning products with no luck. I looked into the active chemical in their cleaning products. The regular cleaner has citric acid(actually sodium citrate 7-13%)as the cleaner. The "Super" cleaner has a little bit more the amount of citric acid(roughly). The stuff won't hurt your engine, but it won't clean my copper radiator either.

    2. I like doing auto repairs myself--yes--I'm cheap.

    3. I plan on using muratic acic(hdrdrcloric acid) to clean my radiator.
    I am going to take the radiator out of the truck and use plastic tape, or
    rubber plumbing vent test plugs(if I can find them) to plug the
    lower and upper hose connections on the radiator.

    4. The Muratic acid from the hardware store is 14.5%. It's pool cleaner from HD. I plan on diluting the acid(yes acid to water), outside, with gloves, a face shield and a carton of baking soda next to me.

    5. Does anyone know the exact percent of HCL that shops use to "boil out" a radiator? I know of the dangers and will take precautions, and I don't condone mixing chemical without
    doing the research.

    6. On another note I just noticed the ingredients printed on the bottle: HC 14.5% and inert ingredients 85.5%. I always thought
    the Abbreviation for hydrochloric acid was HCL? It seems kinda of important in an emergency situation? Like accidental poisoning?
    Maybe HC is just another abbreviation?

    6. Thanks guys--you have saved me lots of money.
  19. Fast Eddy

    Fast Eddy SILVER Star

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    11,665
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    Morgan Hill, CA
    I expect epic 7yo post revivals from newbs. WTH?
  20. subzali

    subzali

    Messages:
    2,648
    Location:
    Denver CO
    When I did my heater core, I just dumped it in straight from the bottle. No need to dilute it if you're taking precautions.

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