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Overflow tank for radiator with brown frothy mixture 700

Noticed what looked to be a creamy coffee looking substance in the overflow tank. Pretty sure this indicates something mixing with the anti-freeze.

Looking at the oil dipstick, it appears dark brown as one would expect. Removing the oil filler cap and looking into the head shows the oil to be in good shape.

Checked the dipstick for the auto tranny fluid. The fluid appears dark red as expected.

Wondering if the radiator has finally deteriorated and there's a mixing between the transmission fluid and the anti-freeze.

Any suggestions to go further to diagnose the problem?
Drain oil?
Drain anti-freeze?
Drain tranny fluid?








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    Overflow tank for radiator with brown frothy mixture 700

    oil in the radiator from the transmission cooling lines- you have a leak in the fitting, or both of them. take out the radiator and resolder the fittings -or get a replacement radiator








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    Overflow tank for radiator with brown frothy mixture 700

    If what you see in the tank is a mixture of coolant and ATF, immediate rescue is needed. If there is a leak in the ATF cooler, which is inside the radiator, water/coolant can get into the tranny, and it's ruinous. The fix is a new radiator and a tranny flush. This works only if the coolant hasn't damaged the tranny.

    Some head gasket breaches allow compression pressure into the cooling system at cold start-up, but the breach closes up when the engine is fully heated. BTDT

    Here's a quick test. With the engine cold, open the hood, remove the coolant reservoir cap and positioning yourself so you can see the reservoir. Start the engine.

    If you see coolant welling up and out of the tank, it's a head gasket problem.

    If may be that you can replace the cap and drive like that for a while. Just watch the temp gauge often and if the needle hits the red, shut down ASAP. Carry some distilled water in the car to top up the tank wherever you are.

    Run the compression test, too. It is a more accurate test. Also look for white exhaust (actually steam) before the engine is heated. Plan for a head gasket replacement soon.

    Goo Luck,

    Bob

    :>)








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    Overflow tank for radiator with brown frothy mixture 700

    Don't drive the car more than a very short distance. Get a cooling system pressure test and a compression test for the head gasket to diagnose where the oil leak is occurring (either in the head gasket or the transmission cooler in the radiator). Get it fixed ASAP before you lose either the engine or the transmission.








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      Overflow tank for radiator with brown frothy mixture 700

      "Get a cooling system pressure test and a compression test for the head gasket to diagnose where the oil leak is occurring (either in the head gasket or the transmission cooler in the radiator). Get it fixed ASAP before you lose either the engine or the transmission."
      I would agree that testing has to be done--but be cautious about the procedures--you don't want to make things worse. Take a compression test first--that may set you in the right direction if the gasket is blown in such a way that compression is being lost. A pressure test on the cooling system may lead to coolant being forced where you don't want it. I'd disconnect the trans cooling lines at the radiator first--pressure from the trans oil may be forcing its way into the coolant -- but you do not want it to go the other way. If the radiator trans cooler section is faulty you may see pressure being lost out the cooler fittings. If the frothy mixture is motor oil there may not be a clean way to tell--the headgasket may be blown or the head surface eroded in the area of the oil transfer between the block and head and putting pressure into the cooling system may force coolant into the motor oil system.
      If you should find it to be a radiator problem--I have 4 of them sitting around waiting for new homes--they're all good--both plastic/aluminum and all metal--they are the type that fit all 240 and early 740----$20 cheap. -- Dave








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        Overflow tank for radiator with brown frothy mixture 700

        Thanks for all the remarks.

        I'll do a compression test this weekend and will flush the coolant from the radiator. I'll drain the oil and tranny fluid to see if there has been any compromise.

        Hopefully it's just a radiator needing replacement. ::fingers crossed::








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          Overflow tank for radiator with brown frothy mixture 700

          just saw this post. brown is oil in coolant, pink is atf in coolant. you have an oil leak. good luck, chuck.








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            Overflow tank for radiator with brown frothy mixture 700

            You're right, but if the ATF has not been changed and is brown, not pink, then it may show up as a brown froth in the recovery bottle. Better to check both head compression and the radiator tranny cooler, especially if the radiator is aging.








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    Overflow tank for radiator with brown frothy mixture 700

    Hello,


    Check the cylinder head gasket. If there is any question:

    Remove and dismantle the engine. Check the castings for damage.

    Replace all gaskets.


    It would be a great idea to replace the radiator if it is original. Pressure test the currently installed unit.



    Goatman







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