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Bleeding cooling system

Discussion in 'Technical and Troubleshooting Torque' started by Seany, May 30, 2006.

  1. [Another first liquid cooled bike question. My appologies}

    I have the radiator of my bike ready for repair. Putting it back on will be no drama, nor will filling and refitting tank etc.. However, I'm a little unsure of how to bleed the air out of the system when it's full. I can't run it with the filler cap off because the cap's under the fuel tank. It'll only be possible if I can find away to run the bike without petrol. :?

    Is it likely that the filler cap is so much vertically higher (nearly a foot) than the radiator in order to minimise bleeding requirements and running it for a few minutes with the cap off the overflow resivior will do the job, or should I be looking for bleeder screws somewhere? :?

  2. Others will be more experienced with this, but my thought is run it for a bit with a fullish resevoir. Stop it and let it cool down. It should pull any water it needs from the resevoir.

    Repeat if it sucks it all in, untill such time as it doesn't.
  3. There will be a bleed screw/s somewhere. My GTR has two bleeders, one at the water pump and one at the thermostat housing. Simply refil with coolant, loosen bleeder screws and wait for coolant to leak out. Retighten and you're done.
    Best to run the bike til hot, let it cool and check again though.
    Oh, and take the opportunity to flush your cooling system while you are at it.
    And check your hoses. Give them a good squeeze, any that are too soft or too hard should be looked at carefully for replacement.

    Regards, Andrew.
  4. Well, I searched and searched for bleeder screws with absolutely no success (both on the bike and google [Yes, I also tried GPZ500 and EX500]). So in the end I checked by using the drain screw onthe water pump (yep water comes out) and the sensor scew in the thermostat housing (yep water again) then squeezed the hoses repeatedly till no bubbles came out and I had a full system. Started it up and ran till hot then let it cool down before checking the resevoir. The level hadn't dropped so as far as I can tell it's hunky dory, though tomorrow's ride to coffee should tell me one way or the other if the job's done. :)

    Thanks heaps for the help guys. I may have more questions later on depending on what that little red light (I wish this thing had a temp gauge) does tomorrow. :)

    For the record, I got some bronze flywire from Mitre 10 and rigged up a gaurd to stop any more pesky stones getting stuck up under that fan bracket. It's effective and bling. :)

    Also for the record, Central Radiator Centre in Fairfield are bloody awesome. :grin: :grin: :grin: