Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Advice needed - bike tampered with, coolant leaking

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by daedalus, May 16, 2011.

  1. Hi everyone,

    I am after some advice.

    Someone tampered with my bike at my work carpark. They disconnected the power to the fan.

    I didn't know and rode it home. Luckily it was mostly freeway riding so there was lots of airflow. However when I got home the slow ride through my apartment carpark must have overheated the bike, and the coolant pipe was sizzling. As the temperature gauge was also disconnected I don't know how hot it got.

    While riding I did notice the temperature gauge and tachmeter was not working but I thought it was just faulty electronics and would get it fixed later.

    I think the coolant boiled as coolant leaked onto the ground.

    After a few days the leaking seemed to have stopped.

    I reconnected everything and went for a ride. This time the temperature was fine (measured by the temp gauge). However when I got home coolant leaked again.

    A few days later the leak stopped.

    Both leaks were not huge - maybe 50ml coolant each time.

    Is this bad? Should I bring the bike for a mechanic inspection?

    My bike is a Kawasaki GPX250 2000

  2. Did you refill the coolant?
  3. maybe you just overfilled the overflow bottle? If your worried its leaking, go to a mechanic and get him to pressure test your radiator (that will show any leaks immediatly)

    2minute job and prollly at no charge (as long as he has clear access)
    Maybe also remove the thermostat and check it opens when dropped into boiling water? (if it dont its stuffed)
  4. no i didnt. should I?
  5. i didnt refill anything so cant have overfilled

    will do as suggested regarding pressure test
  6. If there was very little coolant in it then yes it would boil.
    I would have it flushed and refilled. Don't ever mix coolants. Different brands use different chemicals...not good, some react with others and you could wreck your cooling system.
    And yes get the cooling system pressure checked.
    Why would some prick do that to your bike ???? Is there CCT in the car park ???
    If not rev the guts out of it coming into the car park, and hide and wait.
  7. As your bike gets hot it will expel coolant from the overflow bottle. the problem is that with some bikes, when you get air in them just topping the bottle up wont solve the problem.

    It reads a bit like this is happening to you. Find out if and how you bleed air out of you cooling system. It usually involves cracking a seal at the high point.
  8. Reading the OP it sounds like you have overheated twice.

    the first time it boiled because it had no fans and got hot.

    the second time it would have boiled after you stopped, because the hot engine was heating the liquid during the period before it cooled down just sitting there. This type of boiling happens when your coolant is low, think of it like a kettle. It can take 2 minutes to boil 5 litres, but you can boil 50 mls in about 10 seconds flat.
    There is much more to it than that, but that's the basics of it.

    the 50ml or so coolant you see is not all that you have lost. You would have lost some as steam that you can't see, whilst riding, and more steam while it is sitting afterwards, until it gets cool enough for it to be liquid. You get the liquid you see and then it stops, because now that it is cooling down, there is no pressure to force more out. It is the pressure from the steam that forces out the liquid.

    You need to start by checking the level. Not just the overflow bottle.

    Yes you need to be topping it up if you know which coolant it is using.

    If you don't know, get it drained and refilled.

    Get your fans and lights reconnected, you need these.

    How long have you owned it, are you sure they were working when you got it?
  9. so you think i only need to replace all the coolant and do a complete flush?

    i reconnected the fan and all electronics, they seem fine

  10. Before spending hundreds at a mechanic, "I" would certainly find out the correct method, and top up the coolant, and then go for another ride to see if it makes a difference.

    If you aren't confident about the process though, it may be worthwhile going to a mechanic you trust, explaining that you think your coolant is low, and can they check it out for you. If you ask nicely they may even let you watch and show you how to check it so you know for next time.

    But yes, it may be as simple as just topping it up, it may not even need the flush.
  11. I can't help you with your problem at all but I am interested in hearing someone tampered with your bike? What makes you think it was tamper? Could vibration just have loosened something? What actually happened?
  12. i left it at a private, secured carpark over the weekend.

    i know it was tampered because an electrical connection using big and very tight connectors was disconnected.

    i also need a new battery, so once I buy that I will top up the coolant

    another problem - the previous owner screwed on the screw holding fairing that covers the coolant tank too tightly. i think i may have worn out the screw head. i still can get access via the seat area, but I won't be able to see the line marking the adequate coolant level properly.
    what is the risk of overfilling?
  13. It will just pour out the overflow a bit under pressure. Most full levels are about 3cm from the top :) Or three quarters of the tank
    An engineering shop can drill out that screw and pop a new one in there for you in about fifteen minutes.
  14. alright i have been reading up on doing a full coolant flush.

    Instructions on the internet seems to be:

    1. Undo the coolant drain bolt and place a bucket underneath
    2. Open the radiator cap, the coolant will leak out of the drain bolt
    3. Drain the overflow tank, either by removing hoses or using a siphon
    4. Close the drain bolt? (unsure about this)
    5. Fill the system with water via the radiator hose. When it is full when the bike is off, turn on the engine and run it for a while. Add water when necessary.

    6. Repeat 1 to 4, then repeat step 5 with the new coolant
    7. Top up the overflow tank with coolant if necessary

    Is my understanding correct?

    One question is, why do we need to syphon/remove the overflow tank to drain it? When the drain plug is open why won't the overflow tank also drain via it?

  15. Overflows can sometimes need pressure, or are used under pressure.
    When you drain it you will see if it empties or not anyway.
    What they want is all the old coolant out. Different manufactures use different chemicals to get the coolant affect. And these chemicals from different coolants can react with each other. Rusting your motor from the inside out.
    Another way is to stick the hose in it and flush it. A bit cowboy but it works.
  16. A rather important point nobody seems to have made yet - DON'T RIDE IT until you know how much coolant there is. It may be full, almost full, or almost empty. You may do no harm or you may do a lot. If in doubt, take it to a mechanic, but top up first. If you don't know what coolant is in it, just use plain tap water. It won't hurt anything for a few days, and it should mix perfectly well with just about any coolant.

    You need to get access to the radiator cap, and the overflow bottle. If you can't get the fairing off to get access, then call a bike towing crowd to take it to the shop, or get someone from the shop to come and have a look. Not cheap, but cheaper than a blown head gasket and a warped head.

    [edit] - alternately some good netrider Samaritan might come and have a look at it for you.

    Fill the overflow / vent bottle to the top. Open the radiator cap and fill to the brim. Put the cap back on. Start the bike and warm it up, until the fan comes on. By that point you can be pretty confident the thermostat has opened. Switch off and go make a cup of tea. Come back in half an hour.

    Check the overflow / vent bottle. It should be less than full. Some water should have sucked up into the cooling system. Check that the radiator cap is not too hot to hold your hand on without burning it. If so, wait a bit longer. When you can, open the radiator cap and check the water level. It should be full to the very top. If not, fill it, replace the cap, and warm the bike up again. Repeat the process.

    It may fill right up when you first fill it, so the cool down cycle will be a waste of time, but at least you know it's full. It might take one, two, or even three repetitions. Cooling systems (2 wheels or 4) can get bubbles in them that are hard to get out. You want to get the bubbles out.

    Some cooling systems (not common) are so designed that you actually have to bleed them from the highest point to get all the air out. I don't know if a GPX is like that but I doubt it.

    Somebody mentioned a drain bolt. Some engines have a bolt on the cooling system somewhere that just opens into the water jacket, or waterpump perhaps, so you can drain the system without removing a hose. FJR13s are one example. I know this because I saw it done last week. I don't know if the GPX has a drain bolt, perhaps someone who does know could comment? Anyway - if you opened one up to let the water out, then you need to replace it before ... you get the picture.

    Now you have a full (or nearly so) radiator - ride it to the shop and tell them the story, and ask them to have a look at it.

    Alternately, now that you know where all this stuff is and how it works, loosen off the hose clamp to the lowest connection, and pull the hose. Drain - reconnect the hose. Refill from a new bottle (5 litre should be heaps, 2 litre might not be enough) of coolant. Buy the one with the prettiest label - I don't know which is the best. Go through the procedure described to make sure you've topped it all up correctly.

    Different brands and types of coolant should not be mixed, but if you've topped up with plain water, drained, and refilled, then the amount of old coolant should not be so great as to cause trouble. If you're in real doubt, refill it with plain water a second time and then refill it with new coolant. I think that's being a bit anal, but some would tell you to.
  17. thanks for all the advice guys

    i got an idea - if i drained the coolant via the water pump drain bolt, leave it open and keep adding water to the radiator and turn on the engine will the overflow tank automatically drain?

    is it safe to do this?
  18. Probably not, it generally relies on a pressure differential to pull the overflow back in to the cooling system as that system cools and the internal pressure drops. By having the drain open the system will not be pressurised.
  19. No.

    Why do you want to drain the overflow bottle? Oh, I get it - to remove all the old coolant. Ok, if you can get to the top of the overflow bottle, jam a garden hose in there and turn it on, flush out with tap water. Or get something like a big eye dropper, or a fairly big syringe with a short length of clear tube and just suck it out.

    Refilling everything will be easier if you can get normal access to the radiator cap and the vent bottle. Use the water-pump drain bolt if you like - probably easier than taking a hose right off, but for the refill, stick to the method described above.

    Looking for a good clear diagram of this .... try this one...


    The best way to empty the vent bottle is to unbolt it and tip it upside down. If that's hard, flush with fresh water from the hose. You can suck / pump / siphon it out. You can dip a cloth in it and wring the cloth out and repeat for two hours. You can blow it empty with compressed air, but that'll make a hell of a mess to clean up.

    While I think of it - If you open the water-pump drain plug, get some thread tape and tape it before doing it up.