Radiator pressure caps ?

[Windjammer]

Started having issues with slight overheating? Noticed water/coolant coming from under cap. I am thinking the pressure cap is malfunctioning? Any one have this happen. There is no coolant puddles under bike after parking. It is a 99 IS and have changed the coolant to fresh about 2 years ago. Honda coolant.
Thanks, Regards, Danny

[Airetime]

Bend the tabs and that will tighten the cap

[longrider]

windjammer

I installed  water temp/oil press  gauges a few years back.  A real eye opener.  Since then i have found that the rad gets dirty, bugs fuzz in the fins that you really don't notice.  I remove the rad at least every two years and gently(low pressure) and straight on  wash it with my pressure washer from the backside.  I lay it on a big rag.  It will hold all the crud and I can see what comes out.I just did my 99 tourer as it was running close to 200 in 90 deg heat down the slab last week.  The temp doesnt move off the 185 mark running on it this week.  With no temp indication you could be running close to the fan cut in often and never know it creating a bit more pressure than it should even though it will hit the 212 mark at the lights etc. Just my thoughts

warren
5054

[Ricky-D]

Coolant leaking from the cap would indicate that the return line to the coolant reservoir is clogged.  The cap could still be functioning properly holding pressure at the correct level.

The cap is a two function sealing unit, one to seal the radiator with pressure and the other to seal the cap to make a closed system which includes the reservoir.

Overheating is another issue that may or may not be related to the leaking cap.

I'd suggest looking to insure the radiator is completely filled to the top and the reservoir is at the correct level.

There can be many reasons for overheating the motor. Just to mention a few: Too advanced ignition timing, malfunctioning water pump, blocked air flow to the radiator.

If the fan comes on and cycles on and off I would say there is no problem with your cooling system and you have no overheating problem.  You do not indicate how you have determined there is a problem.

***

[asfltdncr]

Hi Windjammer,
I've had the same problem twice and and this is what fixed it on both occasions:
1.  If you have had your cap off recently, there may be a sliver of aluminum on one of the seating surfaces of the cap-clean and reinstall.
2.  If you removed the cap with set screw on, it may have mis-shaped the radiator throat slightly.In this case, I filed gently to get a true,flat surface for radiator cap to seal to.

Make sure if you sand or file,put rag in throat so nothing goes into radiator and don't get overzealous with the file.

More than likely-just debris on gasket surface.

[Windjammer]

Coolant leaking from the cap would indicate that the return line to the coolant reservoir is clogged.  The cap could still be functioning properly holding pressure at the correct level.

The cap is a two function sealing unit, one to seal the radiator with pressure and the other to seal the cap to make a closed system which includes the reservoir.

Overheating is another issue that may or may not be related to the leaking cap.

I'd suggest looking to insure the radiator is completely filled to the top and the reservoir is at the correct level.

There can be many reasons for overheating the motor. Just to mention a few: Too advanced ignition timing, malfunctioning water pump, blocked air flow to the radiator.

If the fan comes on and cycles on and off I would say there is no problem with your cooling system and you have no overheating problem.  You do not indicate how you have determined there is a problem.

***

While riding, Water started spewing up on the right side (At the cap) and got my attention. 2 weeks prior to this the bike was running hot with the red light coming on. I removed the cap and poured in a quart of antifreeze (Honda) That filled it up and I thought was the end of it? Nothing leaking from under the bike or dripping from the bottom hose. Usually makes me think of the waterpump or hoses. Season is just about finished here in Chicago area and my last planned ride is next weekend for a get away. Looks like more added to list of winter projects on the Lady. Front fork seals, remove fairing to replace most bulbs, New Air Filter, Remove rear wheel and grease splines, Change final drive gear oil, Still have original plugs in. Change that and new vent tubes. Should do the Desmog? Maybe. Check bearings to while I have the rear wheel off. Just a to do list as of now.  Oh and check coolant system. (Clean Radiator now) 

[asfltdncr]

[Windjammer, I wouldn't assume radiator is dirty.Just clean cap.Red light may be on because of leak, you became low on coolant.
quote author=Windjammer link=topic=9062.msg71256#msg71256 date=1254509941]

Coolant leaking from the cap would indicate that the return line to the coolant reservoir is clogged.  The cap could still be functioning properly holding pressure at the correct level.

The cap is a two function sealing unit, one to seal the radiator with pressure and the other to seal the cap to make a closed system which includes the reservoir.

Overheating is another issue that may or may not be related to the leaking cap.

I'd suggest looking to insure the radiator is completely filled to the top and the reservoir is at the correct level.

There can be many reasons for overheating the motor. Just to mention a few: Too advanced ignition timing, malfunctioning water pump, blocked air flow to the radiator.

If the fan comes on and cycles on and off I would say there is no problem with your cooling system and you have no overheating problem.  You do not indicate how you have determined there is a problem.

***

While riding, Water started spewing up on the right side (At the cap) and got my attention. 2 weeks prior to this the bike was running hot with the red light coming on. I removed the cap and poured in a quart of antifreeze (Honda) That filled it up and I thought was the end of it? Nothing leaking from under the bike or dripping from the bottom hose. Usually makes me think of the waterpump or hoses. Season is just about finished here in Chicago area and my last planned ride is next weekend for a get away. Looks like more added to list of winter projects on the Lady. Front fork seals, remove fairing to replace most bulbs, New Air Filter, Remove rear wheel and grease splines, Change final drive gear oil, Still have original plugs in. Change that and new vent tubes. Should do the Desmog? Maybe. Check bearings to while I have the rear wheel off. Just a to do list as of now.  Oh and check coolant system. (Clean Radiator now) 
[/quote]

[Ricky-D]

Windjammer writes: "I removed the cap and poured in a quart of antifreeze (Honda) That filled it up and I thought was the end of it? "

Actually, it's the indicator of a need for further investigation.  A quart missing in the radiator is a large issue.

You should never need anything but a few ounces added to the reservoir tank occasionally.

Simply because there are no puddles on the floor is not an indicator of cooling system condition.  You definitely have a major problem that needs to be threshed out. Or, lose the motor.

***

[Windjammer]

 :cooldude:Yup Decided to get into it. Bike officially done for the year.