coolant leak ?

[vb7prog]

recent relevant service:

replaced radiator cap with 1.6 bar aftermarket cap March 2017
radiator coolant flush 3 weeks ago


I was doing an oil change and it went pretty normally, but after inspecting my bike i noticed a small puddle of coolant under the bike near the kick stand (left rear). I looked at the bike and it looks like it came from the coolant reservoir. I cleaned it up and went about my business. Then a day later I noticed another small puddle same place. I decided to check the coolant level, and it was down about 7oz of coolant, I toped it off and ran bike with radiator cap off, no apparent air in the system. I am thinking it is one of the following?

1. Radiator cap is not sealing correctly and its boiling excess fluid into the reservoir and then pushing it out when the engine temp rises after shutting off bike.

2. Small leak in reservoir somehow

3. Head gasket issue (unlikely, no white smoke out of engine)

Any thoughts ?

 

[TownsendsFJR1300]

Go thru and tighten ALL your coolant hose clamps... (good and snug)

Many heat cycles tend to loosen up clamps, rubber to not seal, etc.

Also, look real close where ever a hose connects to metal (aluminum) for any WHITE corrosion. If found, remove the hose, clean up the metal, re-assemble.

You didn't mention your mileage, but at the bottom of the water pump, (star board side) is a small weep hole.

If the WP seal is starting to fail, coolant will leak from there. I don't see how it would travel over to the kickstand area,
so I'd be paying more attention to the hoses and clamps...

 

[TownsendsFJR1300]

Find anything, any updates?

 

[vb7prog]

Find anything, any updates?

no apparent leak anymore, still monitoring, Currently, I am just using the bike for light commuting in favorable weather (so the bike isn't even getting to 4 bars on heat).

2 other notes, coolant reservoir seems bone dry (come to think of it since owning the bike I have never really remembered fluid in the reservoir), and when leak was present it seemed to be using the plastic chain guard to travel from closer to the front.

 

[TownsendsFJR1300]

So you didn't even check the hose clamps?

I have yet to see a leak (especially coolant on the ground), "fix" itself....

Good luck...

 

[vb7prog]

issue located, vertical hairline crack in coolant reservoir also explains why there is never coolant in there

rubber cement ?

replace reservoir ?

 

[TownsendsFJR1300]

issue located, vertical hairline crack in coolant reservoir also explains why there is never coolant in there

rubber cement ?

replace reservoir ?

Simply replace it, not worth overheating / cooking an engine, etc..

 

[ozgurakman]

Just replace it.

 

[lrojasma]

I think your problem is the Radiator cap.

The FZ6 system is supossed to use a 1.1 Bar cap. If you use a 1.6, the pressure on the system will get too high until the cap starts to do its work, if the pressure gets too high, the coolant can be pushed outside in this case, the cooland reservoir.

 

[Gary in NJ]

The OP found a crack in the reservoir 4 years ago.