Cannot locate coolant leak

Information and questions on GL1500 Goldwings (1988-2000)
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Posts: 3
Joined: Mon Aug 31, 2009 9:23 am
Location: Milford, CT
Motorcycle: 1998 GL1500SE

Cannot locate coolant leak

Post by Randy69 »

1998 GL1500SE
6/1/2020: Drained oil and flushed coolant before changing the water pump. Used new hose clamp on the hose going to the new water pump. Ran the bike to burp the system. All is well.
6/8/2020: Went out to the bike to make sure there were no leaks. The bike was not started or used at all from 6/1. Small amount of coolant found in drip tray under the right side of the bike. Cleaned drip tray and added paper towels to identify general location of drip.
6/15/2020: The bike was not started or used since 6/8. No leaks...yeah!
6/22/2020: The bike was not started or used since 6/15...small amount of leak under the right side of the bike. Changed the paper towels in the drip tray, started the bike, ran up to normal operating temperature. Let sit for 10-20 minutes and more small amount of drip under the right side of the bike.
7/1/2020: Frustrated that I cannot see where the drip is coming from. My question is what do I have to take off the bike to be able to see the majority of the hoses in the general area of the tube the radiator cap is on. I suspect a loose hose clamp.
I remember reading some time ago that Honda used a teflon type tape on some coolant system fitting that can be prone to leaking if it isn't removed. Where is that?
Side note...this bike has always dumped coolant over the winter storage here in Connecticut. My guess is expansion due to ambient temperature fluctuations. Over the last month we have had temperatures range from the 50's to almost 90.
Any and all help is greatly appreciated.

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Motorcycle: 1988 GL1500

Re: Cannot locate coolant leak

Post by ct1500 »

After obvious and known leak areas such as reserve tank grommet, radiator cap and lower hoses it is time to remove the fans. Pressurize system with a tester or run engine until hot watching temp gauge (due to no fans) then shut down and with the aid of mirrors and flashlight or remote camera pinpoint the leak area in the abyss.
The tape on radiator openings was a good idea by Honda to keep the hoses from heat welding to the pipes. After many years of service they can get a little leak prone though.
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Re: Cannot locate coolant leak

Post by minimac »

I had a similar issue. After tightening all clamps, checking all hoses (I thought), I couldn't find anything, yet there was still leakage. I took a turkey baster, sucked out a little from the radiator, and no more leak. The overflow hose from the radiator to the overflow tank did not seal tightly and was causing the small seepage.
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Re: Cannot locate coolant leak

Post by Charlie1Horse »

Take the radiator cap with you and go to a local auto parts store that loans tools and borrow (leave deposit) a radiator pressure tester and make sure that you have the right size adapter for your cooling system. Make sure your radiator is full up to the neck and attach the pressure tester. Pump the tester up to no more than 20 lbs pressure (according to OEM repair manual). I would not exceed 15 lbs myself as too much pressure could ruin the radiators. With the lower fairings and the radiator grille off, watch for location of leaks with light and mirror. You should be able to find it this way. If no leak is found you could have a leak between the radiator cap and the reserve tank. That would be my next inspection.

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