radiator cap leaks

[22Dasher]

Ok I have noticed anti freeze seeping out of my radiator cap. This only happens stopped in traffic or moving behind slow traffic. At cruising speeds its all fine. I checked the vent tube and its not plugged so I'm assuming its a weak cap. Ordered one today dang cost 30.00
Has anyone had this issue and if so was it the cap or was there another problem?
Its not running hot and the fans kick in if sitting in traffic so that's all fine.
Just hoping its a weak cap but like to knpw if anyone has had this issue. It has been hot here as well so since I've owned the bike the heat index is hotter than I've had it out since - purchased 4th july

James

[R J]

The little tabs on the cap, squeese them just a tad tighter with a pair of channel locks.     Send me the $30, ya *issed down the drain for a new cap.

[22Dasher]

Thanks I never thought of that. How we overlook the simplist fixes? I did exactly as you said on my break and will know tomorrow if that fixed the seeping. I examined the rubber seals and the smaller one I could see a groove in it where it's been pressed against something in the radiator but other than that everything else looked to be in good shape.

James

[Gunslinger]

The Radiator cap is very weak IMHO. Not to mention it can be a pain to get on and off. When we did the Motor swap on my wife's standard just before InZane I ran into the same issue. We bent the tabs and prayed as there was no time to order a new cap. Have over 3000 miles on the motor since, and other than some initial seeping have had not problems since.

As a side note, I haven't removed the cap on my I/S but it appears to be a little better constructed, and should fit either bike. Might try that as an alternative (If you hadn't already ordered the new cap)

[Patrick]

This may seem obvious, cuz it is, but, there is a set screw holding the cap in place.. Many have not noticed this before trying take the cap off and have buggered-up [another technical term] the neck..Most just throw away that set screw.. If pinching the tabs doesn't work[it should though] then make sure the neck sealing surface is flat/true and smooth.. A little work with a small hammer and a file may correct that if its not flat/true..

[Ricky-D]

You might want to examine the sealing surfaces inside the the cap boss.  Sometime, if the cap is forced off without removing the set screw, damage can occur to the boss.

Strange to me because the main cap seal only seals the path from the radiator to the reserve tank and it is under no pressure. It is the small part of the cap that seals the pressure, which is the important thing in the scheme of things.

Have you checked to see if the reserve tank fills a little when the motor heats up, and correspondingly empties a little as the motor cools?

Another important thing to note is whether or not (after all is equalized) the fluid in the radiator is totally up to the cap sealing surface when you remove the cap on a cold motor.

I guess you blew thru the recovery line to insure it is not blocked. If not, you need to do that. It's a long line.

Another thing that is a possibility is a leaky hose connection right there at the cap boss, or the hose barb is cracked could also be a possibility.

A leaky cap or whatever is leaking, right there would also keep the radiator from pulling back the fluid when the motor cools so there should be a bit of a air pocket inside the radiator (on a cold motor) and a unchanging level in the reservoir.  You should ascertain this is indeed what's happening.

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