[Craig Boucher]

Hey all,

Just purchased a 2018 Rubicon from Honda dealer with only 100km on it.

Noticed at the dealer the coolant was running below the low level mark in tank. So they gave me a jug and I filled it to the lower level. I went for small drive ~5km and noticed that it dropped below the low level again... So I added some more, this time to the upper level. Went for another drive and it dropped again...

Is this normal? Maybe for the 'break in period'? Would there be air in the system that is slowly bleeding out and being replaced by what's coming from the tank?

I've never got any high heat warning lights or anything, but doesn't seem right to keep going low on fluid in reservoir.

Any help is appreciated. Besides that, the bike is awesome. It's the top of the line model, black color with red accents/guards/shocks.

 

[TBRider]

Take it back to the dealer. Have them check it out, you just got it there.

 

[Craig Boucher]

They told me to not fill it passed the low level line, and that the bike isn't through the 'break in period' yet.

I'll be keeping close eye on it.

 

[TBRider]

I've had mine for 2 yrs and it has never taken coolant

 

[[email protected]]

Your best bet is to have the dealer fix it.

However, my dealer is 50 miles each way so I like to figure these thngs out. Then if it does it again when the machine is old and the dealer will change I know what to do.

When the fluid is low in the radiator on any vehicle, the vacuum system of the expansion box tries to suck fluid out of the expansion box and into the radiator and motor. However, air expands and contracts a lot and if it is too low it can't because the air contracts so much. Thus I always wait til a vehicle is cold and check at the radiator. Just don't open that hot.

Then if you consistently see it down too low there you know the expansion box is accepting hot and expanded fluid to flow out, but not putting it back. Sometimes it can be a simple hose leak or old and cracked hose, or disconnected.

Whatever you find out post it here so that others may know.
dc

 

[Craig Boucher]

The dealer I dealt with is over 100miles away... So I'd like to figure out if this is just air purging out or not.

It seems to suck fluid out of tank, but not dump it back out.

So, when cold, should the coolant be filled to the top of the fill cap on the radiator itself?

 

[TBRider]

I know how a lc engine works, yours has had rad work and is working out the air in the system

 

[TBRider]

The only thing I can recomend is to idle the bike and fill the rad and res. You shouldn't have to add fluid on a new bike

 

[Craig Boucher]

Last night I let the bike idle for atleast 15-20 minutes (reving it up and down every so often). The rad was full to the cap, and I filled reservoir to just above the low level line and I marked it with a marker.

As it warmed up I noticed the level in the tank go above my marked line. I believe this is normal as the fluid heats up and expands, it dumps it into the reservoir tank.

So, this morning I go check the level in the tank and now it is below my marked level from yesterday... But looks like a puddle has formed on ground under the rad...

So Im assuming this fluid either got spit out on ground, replaced air that was still in system, got burned up, or mixed in oil...

When the bike was idling I did notice a little bit of white smoke coming from exhaust. But it didnt smoke the entire time the bike idled. Only maybe 2 minuted or so. And the oil dipstick shows what looks like clean oil. Seems like the oil level is a little high though as it is above the 2 little marks on dipstick.

I will try repeating this test but I wont add coolant this time and see if it continues to drop below my marked line. or if another puddle forms..

This is starting to really bother me.

 

[Craig Boucher]

For those who were following this.

I ran the bike last weekend with no issues. Coolant is maintaining the level. Must of been air in the system that had purged out.

Thanks for all the help!

 

[SamUK]

For those who were following this.

I ran the bike last weekend with no issues. Coolant is maintaining the level. Must of been air in the system that had purged out.

Thanks for all the help!

Only just chiming in on this thread.. Having read the above I'd have advised you to fill the coolant to the maximum level and bleed the system.

Glad you got it sorted though