640 Adventure disappearing coolant problem...SOLVED!

Discussion in 'Thumpers' started by Pointman0853, Dec 5, 2005.

  1. Pointman0853

    Pointman0853 Unregistered Gun Owner

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    I finally pulled all the hoses and radiators off my 640 Adventure to try and find where the coolant was going to.

    My local dealer pressure tested both radiators and found the right one leaking up around the filler neck. Further inspection found the overflow nipple to be the culprit. As the radiator cap would vent coolant to the overflow, it would leak out here and evaporate leaving no clues...

    Problem is, the whole thing is made of aluminum, and the nipple is some POS pressed in plastic thing! WTF was KTM thinking on this???

    So now I either need to find a way to have a bit of short aluminum pipe welded on to this impossibly small area, or buy a new radiator... Can aluminum be soldered or braised??? I think not.

    At least It looks like I won't need to be pulling the head off...

    Pointman
    #1
  2. LKN4DRT

    LKN4DRT Mended

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    Could you use epoxy or JB weld?
    #2
  3. craigincali

    craigincali Just hanging around

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    Take it to a good radiator shop, you may be suprised.
    #3
  4. Pointman0853

    Pointman0853 Unregistered Gun Owner

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    SUPRISE! The radiator shop says they cannot fix it by welding....:lol3

    I have some nasty two part epoxy given to me by a friend that is used on cruise missles or some such thing, and I'll try this.

    Ima' bit concerned about long term hot/cold cycles effect on this, but my only other option is to get 'bent over' at the dealership for a new un'

    Pointy
    #4
  5. craigincali

    craigincali Just hanging around

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    Intersting, doesnt sound like it would be that hard to fix.
    #5
  6. clintnz

    clintnz Trans-Global Chook Chaser

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    I cracked my rad a while back & the rad shop fixed it with some epoxy stuff which is still holding 10000km later.

    Cheers
    Clint
    #6
  7. Jim Bud

    Jim Bud Long timer

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    It must be very clean...and free from all grease and wax....and moisture...

    and roughing upthe surface with emery paper will only make it stronger

    If you do the surface prep well. it will be very strong and last a long time....
    #7
  8. rideLD

    rideLD The further the better!

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    Yep, JB weld is about the only thing that will work on a alluminum radiator. People have been fixing motocross radiators with it for years. I had patched a leak on my VFR800 radiator and it was still holding just fine 80,000 miles later when I sold it.
    #8
  9. Castleman

    Castleman Guest

    If you ever have coolant loss without any leaks, pull the gas tank and remove the breather tube that goes to the tappet cover. If its full of white milky snotty goo, replace your water pump seal. Don't remove the LC4 head looking for a leaky head gasket.
    #9
  10. Beez

    Beez Given to fly

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    Before you buy a new one (if the epoxy doesn't work) give Mylers a call. They specialize in motorcycle radiators and might be able to save it. I just had a severely bent rad. from my 450 EXC repaired by them and cannot believe how straight it is now. :eek1 :D Cost me $70.00 including shipping, new is $199. Infact, you may want to call them BEFORE you gunk it up with epoxy. Good luck.

    If the link doesn't work their number is 800-367-7699.
    #10
  11. Hornet

    Hornet Been here awhile

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    I second the Myers suggestion. When I got my DR650, the radiator was 'customized' by the previous owner in a drunken rage with a crowbar. They patched a small leak and straightened it out beautifully. The results were remarkable and the damage is not even noticable.

    $80 including shipping and the turnaround was a week and a half (shipping from New Jersey to Utah and back included!).
    #11
  12. mazuko

    mazuko mazuko

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    I will third that motion...

    I got my radiators back so fast is was silly... It only cost me $75 to fix the radiator on my old rmx 250. That radiator was crushed, and bent. It worked perfectly when I got it back..

    He keeps his tricks secret.
    #12
  13. KTM640Dakar

    KTM640Dakar Motorsick

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    Your radiator can be TIG welded.
    #13
  14. GODSPEED

    GODSPEED finger lickin' good

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    DR650- radiator :scratch
    #14
  15. PackMule

    PackMule love what you do Super Moderator

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    Oil cooler? :dunno
    #15
  16. creeper

    creeper Still alive...

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    Your not the first to have an issue with this plastic nipple. There have been at least 2 others on this forum that have had similar problems.
    There are shops that can weld and repair your radiator... replacing the plastic with a alloy nipple.

    ICW comes to mind off the top of my head.
    _________________________________

    Maybe I'm missing something here as I don't know the whole story, but this statment has me concerned. Venting should not be considered a common or normal occurrence.
    You still have some sort of issue here. In over 3 years of ownership, my '03 640A has vented a small amount of coolant maybe 2 or 3 times... only in summer on tight, steep single-track.

    C
    #16
  17. GODSPEED

    GODSPEED finger lickin' good

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    That was my thought as well.
    #17