Solved....see last post--------Coolant out the radiator cap question.

[wiggydotcom]

Bought my current bike two and a half years ago. Coming home from Inzane, I was sitting in stop and go traffic and the fan came on as usual but the coolant temp light also came on a couple times. I was able to get to a turnoff and get the bike home with no further incidences.
Upon getting home, the coolant was just above the high mark in the overflow tank.

I decided to change my coolant since I had some Honda coolant on the shelf. I drained the old stuff and it looked pretty good...still clear green like the original. I also drained and cleaned the overflow tank.

I only had 3 quarts of the Honda stuff so I put that in and then topped off the radiator with Prestone 50/50 mix silicate free stuff. I didn't really measure it, just poured till the radiator was full. I also filled the overflow tank to the upper line.

I started the bike per instructions and let it idle with the radiator cap off for about 3 minutes. I then blipped the throttle a few times to try and clear any air bubbles.

Upon taking the bike for a ride, coolant began coming out of the radiator cap...not a steady stream but more than a weep. It didn't quit and now I'm wondering the cause.

Possible thoughts...
Did I overfill the radiator? Not likely, imo.
Do I need a new cap because it's not holding pressure?
Is there still air in the system that needs to be purged?
Do I need a new thermostat because it's not opening? I was always moving and am not sure the fan actually came on after changing out the coolant.

Sorry this is long but wanted to give good info surrounding the incidence.
Thanks to any that can offer insight!

[pancho]

You may need to fill the radiator a couple of times until all the air is gone, but if fluid came from the cap the two most likely causes are,

The cap or it's seat on the radiator need cleaning or other attention, or the tubing to the "overflow tank" is pinched somewhere along it's length.

[wiggydotcom]

You may need to fill the radiator a couple of times until all the air is gone, but if fluid came from the cap the two most likely causes are,

The cap or it's seat on the radiator need cleaning or other attention, or the tubing to the "overflow tank" is pinched somewhere along it's length.

I wouldn't disagree with your cap/seat thought, Pancho. I'm also thinking that is the main culprit. I did fire the bike up a bit ago and let it idle until it got hot. The fan kicked in as it should but I still got a lot of coolant out the cap, especially if I blipped the throttle. I have a new cap and gasket on order as well as a thermostat(never hurts to have a spare)but will check the overflow tube as the overflow tank is still at the same level even thought I've lost a fair share out of the radiator.

I might try to play with the tabs on the cap to see if I can make it seal tighter. It does seem to have a little bit of wobble when screwed on.

Thanks for your input!

[pancho]

If you pull the overflow tubing off the radiator neck, you should be able to blow through it easily into the overflow tank.  Where the tubing passes over the top of the radiator is a likely place for it to get pinched.

[Patrick]

Did you remove the retainer screw before removing the cap ? Or, was the cap already removed ?

Its possible to tear the neck if this screw isn't removed prior to cap removal.

Some folks have taken a file to the neck to make sure its perfectly flat to get the cap to seal.

Also, sometimes it helps to 'put the squeeze' on the retainer tabs to add just bit more pressure.[ just a little]

[wiggydotcom]

Did you remove the retainer screw before removing the cap ? Or, was the cap already removed ?

Its possible to tear the neck if this screw isn't removed prior to cap removal.

Some folks have taken a file to the neck to make sure its perfectly flat to get the cap to seal.

Also, sometimes it helps to 'put the squeeze' on the retainer tabs to add just bit more pressure.[ just a little]

Thanks for chiming in, Patrick. Yes, first thing I did was loosen the retaining screw before removing the cap. I actually backed it all the way out. I do have a chrome cover over the original cap but that's never been an issue up till now. Looking at the picture below, I'm not sure at what angle the two locking tabs should be, slightly upright like in my picture, or straight across, parallel with the cap.
When my new cap arrives, I'll be able to compare em...but then again, this isn't rocket science..it shouldn't be too difficult to figure out. grrrrr

[wiggydotcom]

Did you remove the retainer screw before removing the cap ? Or, was the cap already removed ?

Its possible to tear the neck if this screw isn't removed prior to cap removal.

Some folks have taken a file to the neck to make sure its perfectly flat to get the cap to seal.

Also, sometimes it helps to 'put the squeeze' on the retainer tabs to add just bit more pressure.[ just a little]

Thanks for chiming in, Patrick. Yes, first thing I did was loosen the retaining screw before removing the cap. I actually backed it all the way out. I do have a chrome cover over the original cap but that's never been an issue up till now. Looking at the picture below, I'm not sure at what angle the two locking tabs should be, slightly upright like in my picture, or straight across, parallel with the cap.
When my new cap arrives, I'll be able to compare em...but then again, this isn't rocket science..it shouldn't be too difficult to figure out. grrrrr

Thanks to everyone for their suggestions. I first checked to make sure the line was clear back to the overflow tank and it was. Then I took Patrick's advice and bent the tabs down quite a bit from where they're showing in my pic . They're now straight across and parallel with the bottom of the cap. I'll still put the new cap on as this one might be original and 15 yrs old. It must have had a good seal even with the tabs in their previous position but once I removed the cap for the coolant change, it couldn't re-establish that seal.  Thanks, Patrick!

[Patrick]

Glad its fixed, whatever it took to do it.

[doniholcomb]

When you put the old car back on did it fix it?  I changed my water pump last weekend and now the antifreeze is bubbling out from under cap,  I will look at my cap today and see if my lips are not level or need to go down some more,  will order a new car anyway but want to ride this weekend and have a quick fix for now.

[wiggydotcom]

When you put the old car back on did it fix it?  I changed my water pump last weekend and now the antifreeze is bubbling out from under cap,  I will look at my cap today and see if my lips are not level or need to go down some more,  will order a new car anyway but want to ride this weekend and have a quick fix for now.

Actually, I'm still running with the old cap and the tabs bent back down and there's been no leakage since. I do have the new cap in my trunk just in case.