radiator coolant level too high?

Discussion in '80-Series Tech' started by mainemike, May 2, 2008.

  1. mainemike

    mainemike

    Messages:
    534
    Location:
    Central PA
    The level in the overflow bottle has been dropping since I had the PHH replaced a couple months ago. Haven't noticed any leaks, but since I park on a dirt lot it's hard to notice. Figured I'd run a dye to see if any leaks show up... odd thing is the coolant level is consistently very high at the rad cap. So high it won't take any dye!

    I blew through the overflow hoses to make sure they were open... which they were.

    Why would I be dropping coolant level in the overflow bottle yet be maxed out at the radiator cap? Could something be clogging up in the rad system, or a sign that the HG is weakening? Blackstone shows no antifreeze in the oil. Original radiator. All major hoses less than 2 years old.

    Any ideas?
  2. breathed

    breathed SILVER Star

    Messages:
    383
    Location:
    Northwest CT
    I don't believe the coolant level in the radiator will drop until the overflow reservoir is empty. Coolant could also be leaking into a cylinder. You could check the spark plugs and see if one is significantly cleaner than the others from being steam cleaned.
  3. mainemike

    mainemike

    Messages:
    534
    Location:
    Central PA
    Good to hear the high level at the rad cap is normal... but if that is the case, how does one do the dye test?
  4. e9999

    e9999 You want to do what...? Moderator

    Messages:
    15,269
    Location:
    PRK
    the rad is supposed to be full to the cap, as it expands into the overflow bottle and draws back from it. You should still be able to add a small amount of dye. But if not, just take a bit out or put it in the overflow bottle and it will eventually mix in.
  5. sseaman

    sseaman

    Messages:
    1,736
    Location:
    Nashville, TN
    did you make sure there wasnt any air in the lines when you did the phh, if so as it expells the air it is going to draw in more coolant
  6. mainemike

    mainemike

    Messages:
    534
    Location:
    Central PA
    I didn't do my own PHH so that is a distinct possibility. It's only dropped about an inch in the overflow tank. I just may be paranoid about monitoring coolant levels... I could add some to bring the overflow bottle up to mid-level.
  7. anderaa13

    anderaa13 SILVER Star

    Messages:
    253
    Location:
    Fort Collins, CO
    I bet you just had some air in the system. If this is the case the level in the overflow bottle should level off.
  8. Yes you are. But a wise man knows his faults and limitations. :D

    Drive it for a few weeks and see if you're still loosing coolant in the overflow. However, I would expect, due to evaporation, etc. that occasionally one would need to add a bit to the overflow tank.
  9. hj60

    hj60

    Messages:
    1,512
    Location:
    Ahwatukee, Phoenix, AZ, USA
    You are correct sir. An open system like ours is expected to lose a small amount of coolant every warmup cycle. Over the course of an oil change, it may even be noticable, depending on outside temps and driving habits.
    Check it at every oil change. Top it off whenever necesary. And don't worry about it until it becomes more than just "noticable". .)
  10. sseaman

    sseaman

    Messages:
    1,736
    Location:
    Nashville, TN
    take a sharpie and make a mark and then check a couple days later. do it while it is cold, before expansion occurs

Share This Page