Anitifreeze boiling and venting out after service.

Discussion in 'Thumpers' started by Kaineb, Apr 30, 2007.

  1. Kaineb

    Kaineb Mud Magnet

    Joined:
    Dec 31, 2006
    Oddometer:
    185
    Location:
    Raleigh, NC
    Recently did a bunch of work on my ktm and rebuilt the water pump. After emptying all the fluids i put back in 1 liter of 50/50 mix from local Honda shop that they recommended.

    After riding for a while and about 30 or so miles, came to a light and the antifreeze was bubbling out of the vent tube at a moderate rate. Enought to make a small puddle when i left. Continued home and noticed when i shut off the engine that the antifreeze was boiling :huh. Did i do something wrong? No overheat light or anything like that came on.

    FYI temp was 85+ today.

    Thank you for your assistance.
    #1
  2. Ruffus

    Ruffus Dirty Old Mudder

    Joined:
    Jan 22, 2006
    Oddometer:
    4,245
    Location:
    Fort Erie,Ontario
    coulda been air pockets in the cooling system ( needza good burping), or water pump not working correctly? any chance of a blockage in the rads?
    #2
  3. Kaineb

    Kaineb Mud Magnet

    Joined:
    Dec 31, 2006
    Oddometer:
    185
    Location:
    Raleigh, NC
    Well i took both rads off and flushed them both ways to make sure there was no crapola in there during the service. They were flowing fine. and nothing came out of them abnormal.

    And the fan is not on all the time. It comes on once in a while when i stop. It does come on just a little sooner than before the service.

    Oh and FYI this is not the first ride since the service. Its just the first long one. I had done some woods riding a couple of times for a few hours and didnt really notice either way.
    #3
  4. Ruffus

    Ruffus Dirty Old Mudder

    Joined:
    Jan 22, 2006
    Oddometer:
    4,245
    Location:
    Fort Erie,Ontario
    Time for a new rad cap? if it opens too soon or doesn't hold its designated pressure, fluid will boil at lower temps & will spew into the overflow. Sorry, thats the only other thing I can think of. Hopefully someone with the same bike has a good direction for you to check. Good luck
    #4
  5. cevquit

    cevquit maphead

    Joined:
    Jul 7, 2006
    Oddometer:
    637
    Location:
    At the foot of the mighty Sierra Nevada
    If the radiator is too full it will puke it out as it gets heated up, till it is at the proper level. Mine settles out at a 1/4"? above the passages inside the radiator. Might want to check the thermostat to make sure it is opening.
    #5
  6. GaelicDog

    GaelicDog Lesser of Two Weasels

    Joined:
    Jun 3, 2004
    Oddometer:
    7,324
    Location:
    Atlanta, GA
    What is the easiest way to determine the pump is pumping? Is it like a car, remove the cap and see movement?
    #6
  7. MookieBlaylock

    MookieBlaylock Long timer

    Joined:
    Feb 29, 2004
    Oddometer:
    2,584
    Location:
    IntheeaglewingpalaceoftheQueenChinee
    bleed screw used ?
    #7
  8. flan8tive

    flan8tive Flea Tibet!

    Joined:
    Oct 6, 2006
    Oddometer:
    2,188
    Location:
    Center of the Humidiverse
    Do you have a 1.2 bar or 1.4 bar radiator cap. Maybe go to a higher bar rating.
    #8
  9. Kaineb

    Kaineb Mud Magnet

    Joined:
    Dec 31, 2006
    Oddometer:
    185
    Location:
    Raleigh, NC
    I am not sure if it's a cap issue, and the bike would have overheated if the thermostat was closed or the pump wasnt working and no circulation was happening at all. All of the lines were pretty damn hot.

    One thing i saw was that the manual calls for topping the bike off running 10 mm above the "grid" of pipes inside the right radiator. When i put the 1 liter in described by the manual i actually only had a 920 ml bottle of AF. It never came above the grid at all and i am not sure since i completely drained the system if i should have put more in.

    So... could this happen if you do not have enough antifreeze? Boiling and overflowing and such?
    #9
  10. eskimo

    eskimo gunga-galunga

    Joined:
    Feb 18, 2004
    Oddometer:
    941
    Location:
    Arizona Riviera
    My 640e kept pukin' water and I thought the worst. Found a microbe of crud under the radiator cap seal, removed it, and all has been fine since. Just sayin'
    #10
  11. halfcab

    halfcab Been here awhile

    Joined:
    Apr 6, 2007
    Oddometer:
    687
    Location:
    Dog Patch S.C.
    Is this an LC4 with the fan, is the fan working.
    Or an RFS motor?
    #11
  12. Dotbond

    Dotbond Africa, Africa

    Joined:
    Jun 18, 2006
    Oddometer:
    896
    Location:
    Dunedin. New Zealand
    Same prob a couple of weeks ago. Same fix as well.
    #12
  13. bmwktmbill

    bmwktmbill Traveler

    Joined:
    Jul 16, 2005
    Oddometer:
    5,986
    Location:
    Traveler
    Kaineb,
    My 2 cents.
    Are you sure you are boiling?
    You need a thermometer to check the temp gauge.
    Fill the radiator with water, water and antifreeze, anything but get it full-not too full(a little above the plates, below the neck) .
    Run it at idle, on the stand. Cap off.
    Stick a thermometer in the radiator tank and check the temp.
    The system will run and cool with the cap off.
    Look down in the tank and see what is going on.
    Note at what temp the fan comes on?
    Put the cap on tight. Run the bike on the stand.
    If you are really boiling when you now remove the cap all hell will break loose.
    Water will fly or a hose will start leaking.
    If you really are boiling remove the thermostat and do all of the above again.
    Report back.
    Be careful doing all this. You can get burned or wreck the bike. Just do it enough to make the tests.
    bill.
    #13
  14. Kaineb

    Kaineb Mud Magnet

    Joined:
    Dec 31, 2006
    Oddometer:
    185
    Location:
    Raleigh, NC
    First off thank you all for your assistance. Really great having a world of knowledge on demand :)

    I found that i needed to add about 300 ml to be at the proper level this morning. 200 50/50 mx and 100 distilled water for the proper ratio. 60/40. I ran the bike as you described (bmwktmbill) and i do see flow in there.

    My thoughts that the bike was boiling was purely the sound when i shut the bike off. Sounded like it.

    I ran the bike cap off filling first to the proper level with af as decribed in the maual. I found that i did see flow in there and the fan is coming on when it is supposed to.

    Crud in the cap: Mine had allot when i first serviced the bike, in which i didnt do such a good job at cleaning it so i will do that now. I didnt even think of that.

    Again thanks for all the help. We are making progress, just not there yet.
    #14
  15. Kaineb

    Kaineb Mud Magnet

    Joined:
    Dec 31, 2006
    Oddometer:
    185
    Location:
    Raleigh, NC
    Cause: Improper coolent level / mixture & Buildup of material on filler cap / radiator neck.

    Resolution: Cleaned out the neck of the radiator using a punch to scrape the area and vacccum to avoid getting anything in the system. Cleaned all the seals on the cap and cleaned the indise of the neck.

    Topped off the fluid level with proper mix and level and took for a long ride. No issues and no leaking now.

    Thank you all for your help. I am sure the dealer would have loved to have fixed that simple issue for $200+
    #15
  16. Dotbond

    Dotbond Africa, Africa

    Joined:
    Jun 18, 2006
    Oddometer:
    896
    Location:
    Dunedin. New Zealand
    Excellent result.
    #16
  17. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,552
    Location:
    Circumlocution Office of Little Dorrit
    bookmark. good work kaineb. glad you found it before you dealer did :)
    #17
  18. thouk

    thouk Been here awhile

    Joined:
    Apr 11, 2006
    Oddometer:
    249
    Location:
    Lincoln, Ne my hometown, Where I'm freezin
    Hello,
    This sounds like the same symptoms that my bike, Xr650r, is going through. I recently replaced the water pump and the fliud along with all the hoses. THe bike was leaking fluid that I found out to be a loose hose clamp. Now it is still venting fluid. I used Evans NPG+ instead of the normal ethylene glycol. I looked at the radiator cap to see a little crud on it at the sealing base place. I have not taken the bike for a ride since cleaing the crud off as recommended but I hope that helps to keep mine from spitting the fluid. One thing that I have noticed with mine is that when I get done riding and I go to check the fluid for the correct volume, I do hear a vacuum break sound indiciating the system is under vacuum. When I open the cap I have noticed that the overflow catch can is full but the radiator did not draw up the over flow volume and the radaitor is low. Before I cleaned off the crud I did notice while I was riding the catch bottle was bubbling like it was collecting the overflow from the radiator. Can anyone tell me why the radiator is not using the vacuum that it has to draw the fluid back into the radiator?
    Thanks, Tony
    #18
  19. bmwktmbill

    bmwktmbill Traveler

    Joined:
    Jul 16, 2005
    Oddometer:
    5,986
    Location:
    Traveler
    Hey Thouk,
    I am not the wiz on radiators but I do have some common sense.

    First of antifreeze does nothing for cooling, it keeps the water in the system from freezing.

    The radiator cap is a pressure cap that releases internal pressure that builds up if the system runs too hot because liguids expand when heated and go nuts when they boil, especially water which is not entirely a normal liquid.

    Vacuum occurs when things cool down, volume shrinks in a closed system making a slight vacuum. No biggy. Normal.

    It beats the heck out of me how a radiator can suck fluid out of an overflow tank through a pressure cap. Maybe the spring and seal relax enough to allow suction.
    Someone has to explain??

    If you think you are boiling do the test I wrote about earlier.
    Not sure why you Honda needs an overflow tank but I don't know the bike.
    bill
    #19
  20. meat popsicle

    meat popsicle Ignostic

    Joined:
    Feb 9, 2004
    Oddometer:
    14,552
    Location:
    Circumlocution Office of Little Dorrit
    Evans NPG+ is thick, so maybe it is too thick for the vacuum to draw it back into the radiators? :dunno

    Anyways, I have something like this going on, so I will be looking closely at my cap and next. Thanks again Kaineb :beer
    #20