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Coolant..everywhere

Discussion in 'Early CJ5 and CJ6 Tech' started by jeepstar, Sep 30, 2016.

  1. 73 cj5

    73 cj5 Not ready for the junkyard yet

    Always replace your gasket at the same time. You can try to tighten that bolt and see if the leak persists, but I doubt that's going to change anything. If it's the seal replace the pump with a high quality unit.
    Also like ITLKSEZ said check your radiator cap pressure,,,
    Too high a pressure cap and it can blow the seal again
     
  2. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member

    Pretty muck guaranteed you need a new pump- BTDT.

    I don't think that's the cause of your incident, you need to dig deeper.

    H.
     
  3. jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Suggestions howard?

    Get a lower pressure cap?
     
  4. 73 cj5

    73 cj5 Not ready for the junkyard yet

    How many psi is your current cap rated at?
    Ever run the engine with the radiator cap off and see bubbles?
     
    Chilly likes this.
  5. jeepstar

    jeepstar Well-Known Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    No idea what it's currently rated at. And I have never ran it without the cap on to watch the bubbles. What would that tell me?
    And of course I would change the gasket when I change the pump I don't know if I should just replace the gasket or the pump (and gasket)
     
  6. 73 cj5

    73 cj5 Not ready for the junkyard yet

    Bubbles would tell you there is a fault in the head gasket (exhaust gasses). Ways of telling that you have a blown head gasket are: White smoke/steam from exhaust, milky oil, overheating, loss of coolant, external leak, excess build up of pressure in cooling system. It's possible to have a blown head gasket and not see coolant/oil mix or the steam/smoke. Not saying you do have a blown head gasket, just gotta rule out all the possibilities. Psi rating is usually cast into the radiator cap or on the cap sticker. Leave no stone unturned,,,
     
  7. 47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    ha, you beat me to an almost exact post.
     
    73 cj5 likes this.
  8. Chilly

    Chilly Active Member

    Coolant leak into cylinder will sometimes also result in steam-cleaning the piston dome and plug.
     
    73 cj5 likes this.
  9. ITLKSEZ

    ITLKSEZ Hope for the best, prepare for the worst

    So it is leaking only out of the gasket?

    Normally, I'd recommend swapping the pump while you have it out to change the gasket, but the way things are built these days, you might be better off just running the one you have. Chances are, it will run longer than anything new. I know the one that is in my F-head had been there for many years before I got it 20+ years ago.

    I checked Rockauto, and all of the caps they list for that engine are 13psi. If yours is anything above that, I'd probably swap it out. Like was stated, the pressure rating should be stamped or printed on your cap. If not, swap it regardless.

    The higher the pressure, the higher temps you can achieve without boiling. These old engines aren't designed to run any hotter than ~220; any higher temp or pressure and your just asking for trouble, and a more violent and damaging blowoff when something does go wrong.
     
  10. Howard Eisenhauer

    Howard Eisenhauer Administrator Staff Member


    The cap , if it released, is working properly whether it's a high or low pressure unit- pressure built up higher than it's supposed to & it vented. The question is why is the pressure building up?

    Too hot?​

    Exhaust gases in the coolant?​

    You need to find the root cause.

    H.
     
  11. Walt Couch

    Walt Couch sidehill Cordele, Ga. 2024 Sponsor 2023 Sponsor 2022 Sponsor

    If you over fill the radiator, it will push out excess fluid as needed (sometimes). The top of the radiator has to be empty of fluid for expansion of fluid.
     
  12. tarry99

    tarry99 Member

    Replace them , Water pumps are cheap so is the gasket and a correct cap..........If you have a way to pressure test the system you can try that first , But with that bolt loose it will still leak and I assume those threads go directly into the water jackets so they also need to be sealed..............Carry On!
     
  13. montanacj

    montanacj Member

    This won't be a hard job for you even with limited experience wrenching. Just take your time and don't over tighten the bolts.

    The sure fire way to test for head gasket leak is to test the coolant for hydro carbons, this would require specific equipment or a block tester you rent at a FLAPS
     
    Last edited: Sep 30, 2016
  14. Glenn

    Glenn Kinda grumpy old man Staff Member

    2 things I see wrong. That bolt needs to come out and have sealant put on the threads as mentioned. The fan belt is not the right width, it rides too low in the pulleys. Maybe it's not slipping but if it is then the water pump isn't spinning as fast as it should. The puff of white smoke is definitely concerning. Check the oil for coolant, and get a 7lb radiator cap.
     
  15. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    If you lost enough coolant fluid from the water pump, that would eventually cause a steam eruption from the radiator.

    Another time that happens is if there is air trapped in the block, after refilling coolant, and it needed to be burped.

    A leaking head gasket can cause a similar result. Or a faulty thermostat, or a radiator cap with a pressure rating too low for the thrmostat temperature.

    For sure replace the pump in any case.
     
  16. ETZFAM

    ETZFAM FLATIES & ROUND FENDERS, SOME EVEN RUN

    When I rebuilt my L head years ago, i could not find the old radiator cap for it, put a 7# cap on it, it over heated, water came out the head studs, etc.

    I finally put a 3# cap on it and no problems?
     
  17. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    I don't understand that - seems backwards since the higher pressure cap should actually raise the boiling point.
     
  18. Keys5a

    Keys5a Sponsor

    Before I did anything else, remove that loose bolt (your finger is pointing to it in post#16) and put some sealer on the threads. Re-install the bolt and tighten it. That may be the whole problem. If the bolt is already bottomed out, you may need to find a shorter bolt.
    -Donny
     
    eti engineer likes this.
  19. Glenn

    Glenn Kinda grumpy old man Staff Member

    I agree, I don't understand the overheating part. The studs should not have leaked unless they didn't have sealant on them.
     
  20. eti engineer

    eti engineer Member

    2X on what Keys5A said. The more I read, the more I was thinking this. Could be wrong, but I would give that a try before anything.