Why is my 800GS squirting coolant fluid UP at me?

Discussion in 'Parallel Universe' started by GB, Aug 18, 2010.

  1. AlanI

    AlanI Adventurer

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    Leaving aside the why's and wherefore's of this for a moment, I think it can be taken as read that under certain circumstances/events leading to over-pressurisation of the cooling system that coolant is being vented to atmosphere via the little hole in the top of the expansion cap. As this can, and it appears does, result in coolant being blown into the face of the rider then I seriously believe that this urgently needs bringing to the attention of BMW. By that I don't mean a quick word with someone in your dealers workshop but a formal letter/email bringing a serious 'safety issue' to the attention of BMW HQ. There may well be instance where the rider doesn't have the visor closed, standing at traffic lights etc where coolant being blown into one's eyes results in chemical contamination of same. Or, if on the move, a sudden and unforeseen flash of liquid on the visor could result in a serious accident.

    This is obviously a failure in design and the remedy to it is quite simple. If you think back to radiator caps fitted to cars (pre expansion tank days), when the spring on the cap lifted as a result of over-pressurisation of the coolant system, the pressure was also vented by a hole but in this case the hole had a short length of rubber tubing fitted to it that pointed in a downward direction. In my opinion the current expansion cap could easily be redesigned that either incorporated the rubber tube method or, a pre moulded elbow could form part of the cap with it's opening pointing downwards - much like the elbow fitted to batteries. However, if this matter is not brought to the attention of BMW themselves then nothing will change and perhaps one day we shall read on this forum of another such event but without the happy ending.
    #21
  2. GB

    GB . Administrator Super Moderator Super Supporter

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    GrizGirl and PU Inmates, thank you.

    I had a look at the expansion tank and it is filled to the very top, past the max line, from the factory. There is a small hole in the expansion tank that is squirting fluid at me at these high altitudes. Temp fix will be to make a duct tape arch over the cap which will permit it to vent, while Touratech comes up with a farkle for it.

    The expansion tank cap needs to have a side vent, not a top vent.
    #22
  3. Scootercycle

    Scootercycle n00b

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    At the F800 forum, I was advised that there was air in the coolant system. It was bled it out and top it off. It was a good call because that was the problem and the service department confirmed it.

    FYI, you can get air introduced into the system in various ways:

    1. You drop the bike in manner that allows an air bubble to get back down the system
    2. There's debris in the radiator cap as you close it, creating an air gap, or faulty cap
    3. Did not bleed out the air fully when you filled with coolant
    4. Hose not sealed at connections completely or pin hole somewhere.

    Things won't get better on their, it'll only get worse. The air bubble will eventually heat, expand (gas expands more than liquid) and push out the geyser from the relief pinhole on the cap at the overflow container. The proper fix is to bleed out the air in the system. The bubble will also reduce or stop the coolant system from working properly....generating more heat.
    #23
  4. KL0RG

    KL0RG Adventurer

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    Had this issue start happening to me while I was on a ride down in the PNW, was just after a 6k service. Stopped at a dealer on my way back and asked the service writer about it, he had no clue. Ended up back at the dealer that did the 6k and they took the bike into the shop to take a look. After about an hour the manager comes out and says my fan was stuck:huh. Not sure why having the fan stuck would cause coolant to geyser out, didn't measure it but a few times I swear it went 2 feet above my head.
    Anyway check your rad fan and see if it's stuck.
    #24
  5. Ceri JC

    Ceri JC UK GSer

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    Mine did that once early on in the bike's life. Garage says it was overfilled at PDI based on the level. Removed excess fluid, problem stopped.
    #25
  6. GSranger

    GSranger blacksheep

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    :poser

    I was thinking the exact same thing :beer
    #26
  7. GB

    GB . Administrator Super Moderator Super Supporter

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    I've noticed when I'm up above 9000 feet, it squirts a bit of fluid out. My duct tape arch over the expansion tank cap worked well. My expansion tank is filled to the very top, so when the bike goes in for 20K service next week, I will ask them to decrease the level.
    #27
  8. Singletrack_mind

    Singletrack_mind Cave Man

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    #28
  9. Keithy

    Keithy Chaotically Keith

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    So, is the cooling system on the 800 not pressurised?

    I'm struggling with the altitude part too.....As the altitude increases does the amount of air in the system not decrease?

    I'd expect it to spit the coolant at you if you filled the system at the top and then descended to lower altitude.

    What's the boiling point of water in an open system and a closed system....And do the anti-freeze/anti-corrosion additives evaporate.
    #29
  10. Bicyclist

    Bicyclist Been here awhile

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    #30
  11. Singletrack_mind

    Singletrack_mind Cave Man

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    #31
  12. Keithy

    Keithy Chaotically Keith

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    #32
  13. MTrider16

    MTrider16 Ridin' in MT

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    I will have to check my system out. I think I had it at lower altitudes here in MT, but on a hot day.

    BTW it is easy to breat that tab off the radiater, by just dropping the bike without engine gaurds.

    David
    #33
  14. Bayner

    Bayner Long timer

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    When this first happened to me I was at a loss as to what was going on. The second time I narrowed it down to the hole in the reservior cap. (I was not at any significant elevation at the time) What the heck were they thinking in designing this cap? They couldn't put a deflector on the cap or vent it sideways so it doesn't spray directly in your face, especially at speed? It's simply crazy. I lowered the level and all has been well since. I was pretty pissed off when it happened though. It's just so potentially dangerous I have a hard time believing they overlooked the glitch in the design.
    #34
  15. lmclamore

    lmclamore Citation Collector

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    FWIW a form of this happened to me today. No significant altitude changes though. minor spraying from the overflow bottle cap on a few occasions and then a noticeable increase in anti-freeze level in the bottle. Siphoned off the excess and will monitor this week.
    #35
  16. soph9

    soph9 Would Love to ride ALL the TIME

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    yep....we had an over flow issue too....nothing more that...just the service guys filled up the coolant too much
    #36
  17. peekay

    peekay Been here awhile

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    #37
  18. Lounge

    Lounge Been here awhile

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    Happens to me too - Colorado.
    #38
  19. lmclamore

    lmclamore Citation Collector

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    Changes in altitude seem to have a lot to do with this. My coolant situation got worse last year after my post. It started after I rode through some mountains. It ended with too much air in the system causing ineffective cooling. Dealer called it a bad radiator cap. Everything was fine again until I crossed the White Mountains in NH this summer. The overflow tank was "spitting" AF later that afternoon once closer to sea level. I cleaned up the mess and watched closely since then. No issues but I haven'e changed elevation by more than 1000 feet since.
    #39
  20. L.B.S.

    L.B.S. Long timer

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    I live at/below sea level and my 2009 F800ST pisses out the expansion tank's cap vent hole all the time. Fortunately, (I guess you could say :lol3) the bodywork on the ST deflects the stream out the side of the fairing, so it just goes all over my right leg and boot instead of up into my face... :huh

    My coolant level is right at the min line, and has only ever been in to the Dealer for all of it's services, btw.

    A guy on the F800Riders forum installed a small bleeder fitting in the expansion tank cap where the small hole was, and attached a length of clear overflow tubing to that. One could do this, and if not completely eliminate the excess fluid spraying on you, at least direct it away to a place of your own choosing.
    #40