Coolant Concerns

Daniel wrote:
 > ok, here's the thing.
 > when my bike gets hot, it blows the coolant into the reservoir.. so
 > far so good...
 > then it cools down, and it doesnt draw it back in.
 >
Is the radiator actually low on fluid?<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

On 14 Sep 2004 03:28:42 GMT, kaybearjr.RemoveThis@aol.comical (krusty kritter)
wrote:


the end of the hose is submerged, and there are no blockages...



 >OK, so the radiator cap has a vent to relieve overpressure at some point, maybe
 >around 12 pounds over atmospheric pressure and it lets the hot water out to go
 >up a hose to the reservoir...
 >
 >Then, when the radiator cools off, the radiator cap needs to open a vacuum
 >breaking vent, so the radiator header tank doesn't collapse under the pressure
 >of the surrounding air, and the coolant in the plastic reservoir *should* be
 >sucked back to the radiator...
 >
 >The reservoir cap probably needs to be vented to allow the water to flow back,
 >so check for a blocked vent on that plastic cap...
 >
 >Is the end of the hose in the reservoir submerged in coolant? I hope so...
 >
 >
 ># * 0 * #
 > ^
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

On Tue, 14 Sep 2004 09:00:45 +1000, Daniel <> wrote:



radiator is not low on fluid.. i have to top it up every day because
it overflows, and isnt being drawn back in.
 >ok, here's the thing.
 >when my bike gets hot, it blows the coolant into the reservoir.. so
 >far so good...
 >then it cools down, and it doesnt draw it back in.
 >
 >i have replaced the hose between the radiator and the reservoir, and i
 >have replaced the radiator cap.
 >
 >any suggestions?<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

 >From: <A HREF="mailto:Daniel <>">Daniel <>

 >radiator is not low on fluid.. i have to top it up every day because it
overflows, and isnt being drawn back in.

Does your engine have a place to "burp" air out of the system? I have read that
some Kawasakis do have burper valves at the high point of the system, just like
some stationary engines I've worked on...

If the engine isn't overheating, and doesn't have a blown head gasket
(shudder!), maybe there is air trapped in the cooling system which always
maintains enough pressure on the radiator cap to keep the vacuum breaking vent
from opening...

If there isn't a valve to let the air out, the highest point in the system has
to be opened to let it out...



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Daniel wrote:
 > ok, here's the thing.
 > when my bike gets hot, it blows the coolant into the reservoir.. so
 > far so good...
 > then it cools down, and it doesnt draw it back in.
 >
 > i have replaced the hose between the radiator and the reservoir, and i
 > have replaced the radiator cap.
 >
 > any suggestions?

How much coolant is going into the reservoir? the coolant hoses are not
completely rigid, so if there is a negative pressure, the hoses would
collapse just a little to accommodate the lower coolant volume, then when it
warms up, the coolant expands to the normal operating volume. Unless there
is a very large variation in temperature, not much coolant will move back
and forth once its settled in.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

On Wed, 15 Sep 2004 05:53:58 GMT, "Trey" <treydog90spam DeleteThis @hotmail.com>
wrote:

 >Daniel wrote:
  >> ok, here's the thing.
  >> when my bike gets hot, it blows the coolant into the reservoir.. so
  >> far so good...
  >> then it cools down, and it doesnt draw it back in.
  >>
  >> i have replaced the hose between the radiator and the reservoir, and i
  >> have replaced the radiator cap.
  >>
  >> any suggestions?
 >
 >How much coolant is going into the reservoir? the coolant hoses are not
 >completely rigid, so if there is a negative pressure, the hoses would
 >collapse just a little to accommodate the lower coolant volume, then when it
 >warms up, the coolant expands to the normal operating volume. Unless there
 >is a very large variation in temperature, not much coolant will move back
 >and forth once its settled in.
 >


at the moment, im putting about a pint a day in the radiator. there
are no visible leaks, except from the overflow from the reservoir...
and that is fairly gushing when it gets hot enough... i.e. in traffic.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

Daniel wrote:

 > at the moment, im putting about a pint a day in the radiator. there
 > are no visible leaks, except from the overflow from the reservoir...
 > and that is fairly gushing when it gets hot enough... i.e. in traffic.

Head gasket leak between the cylinder and the coolant passage? Does your
exhaust smell at all like coolant?

-Chris-<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

On Tue, 14 Sep 2004 09:00:45 +1000, Daniel <> wrote:

 >ok, here's the thing.
 >when my bike gets hot, it blows the coolant into the reservoir.. so
 >far so good...
 >then it cools down, and it doesnt draw it back in.
 >
 >i have replaced the hose between the radiator and the reservoir, and i
 >have replaced the radiator cap.
 >
 >any suggestions?

Perhaps there is a tiny leak in the hose running to the tank. Rather
than suck back the coolant, it sucks air like a broken straw. Also
check the junctions of said circuit, they are likelier culprits.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

On Tue, 14 Sep 2004 09:00:45 +1000, Daniel <> wrote:

 >ok, here's the thing.
 >when my bike gets hot, it blows the coolant into the reservoir.. so
 >far so good...
 >then it cools down, and it doesnt draw it back in.
 >
 >i have replaced the hose between the radiator and the reservoir, and i
 >have replaced the radiator cap.
 >
 >any suggestions?


there is no noticable smell of anything from my exhaust. i can see no
coolant leaks externally anywhere, except the overflow fromt he
reservoir.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns 

 >From: <A HREF="mailto:Daniel <>">Daniel <>

 > i can see no coolant leaks externally anywhere, except the overflow fromt he
reservoir.

How about bubbles in the coolant with the radiator cap off? You have to do this
test before the coolant gets hot enough to start boiling out of the system
though...

Or, maybe your engine is just running hot from a lean mixture. Carbureted
motorcycle engines will run a lot cooler on hot days if you just open the idle
mixture screw 1/4 ot 1/2 a turn...

The hot weather locally has been giving my old pickup truck problems. It's been
around 100 degrees in the afternoon all summer. My spark plugs indicated that
the engine was running very lean, and the truck was low on power...

I saw some coolant under the engine that was pushed out of the reservoir and
thought for a while that I might have another @#$%^&* blown head gasket...

But, it seems that the engine was just running a bit lean from mild vapor
locking, the electric fuel pump couldn't push enough gasoline through the
gasoline vapors in the
fuel line, or the fuel line was partially blocked, I dunno which...

I cleaned the fuel filter and didn't get much debris....

I blew air back through the fuel hose to blow whatever might be blocking the
fuel hose back into the gas tank...

The old truck runs a lot better now...






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On Tue, 14 Sep 2004 09:00:45 +1000, Daniel <> wrote:

 >ok, here's the thing.
 >when my bike gets hot, it blows the coolant into the reservoir.. so
 >far so good...
 >then it cools down, and it doesnt draw it back in.
 >
 >i have replaced the hose between the radiator and the reservoir, and i
 >have replaced the radiator cap.
 >
 >any suggestions?


thanks for all the comments and suggestions guys. ive booked the bike
in for the scheduled 24000km service on tuesday. ive told them to
give the cooling system a thorough looking at, but not to do anything
without asking me. now i have enough information to be dangerous at
least *grin*.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: Coolant Concerns