Low Water Buzzer

[powersltc]

Ron P.

2004 Monaco Executive,  Cummins 500 ISM.

 

I am having trouble with my coach being low on coolant and the buzzer sounding.  When I stop driving it appears to be leaking from the coolant reservoir hose.  New reservoir.   I can add coolant and the buzzing stops.   After driving about 250 miles,  the low water light and buzzer comes on.  The engine temperature is 177-181 F. 

I recently had  my heater hose to the Aqua-Hot replaced. 

Any ideas/suggestions.   

[Ivan K]

Sounds like you know where it is leaking from so what are you looking for? Or is it the overflow?  If so, have you replaced the reservoir with the same? They are sized to the amount of coolant in the system.

[powersltc]

Yes.  But what would cause the reservoir to overflow?  

[Ivan K]

Coolant expansion, the more coolant in the system, the more volume will go into the expansion tank. It has to be the right size to not overvlow and not be too low when cooled down. Your temps are good, quite low actually. Do you get the buzzer when cold or while at the temp? No bubling when overflowing, I hope.

[David White]

If overflow and not a tank or hose leak, it could be the tank cap has stopped providing to necessary pressure control.  If it’s never been replaced, I would do that.  I’m fact, I went with a lower # cap to avoid a tank rupture.  Never had an overflow with the lower pressure.

[powersltc]

1 hour ago, Ivan K said:

Coolant expansion, the more coolant in the system, the more volume will go into the expansion tank. It has to be the right size to not overvlow and not be too low when cooled down. Your temps are good, quite low actually. Do you get the buzzer when cold or while at the temp? No bubling when overflowing, I hope.

It buzz when cold.  Tomorrow morning I will add coolant.   It will buzz initially,  then stop buzzing. 

[Fonman]

Just to clarify in my own mind. Is what you are calling the reservoir a metal tank with radiator cap or the plastic burp bottle?

i assume you have both? 

[powersltc]

I have the plastic tank with a radiator type cap.

[jacwjames]

What reservoir tank did you install, do you have a part number or link.   A picture would help.

What radiator cap did you put back on, the same as what you had or a new one, if so what pressure.

You say it is leaking from a hose, what hose.  On my surge tank there were 4 connections of hoses, two at the top on the back that were small, one on the top that attached to the fill port where the cap attaches, and one at the bottom that is a larger hose.  Is yours the same, if so what hose is leaking.

Personally I would not be driving this if it was leaking, if it were to loose more coolant you could be stranded on the side of the road if the engine derates or stand a chance damaging your engine if it didn't derate.

[Fonman]

A picture might help.

Can you start up cold with fluids full and let it run until it is good and hot and look for another leak?

Hopefully over a paved surface?

 

Typically expansion by itself won’t leave you with enough loss while still driving to set off the alarm. Only after it cools should you get the buzzer.

[powersltc]

1 hour ago, jacwjames said:

What reservoir tank did you install, do you have a part number or link.   A picture would help.

What radiator cap did you put back on, the same as what you had or a new one, if so what pressure.

You say it is leaking from a hose, what hose.  On my surge tank there were 4 connections of hoses, two at the top on the back that were small, one on the top that attached to the fill port where the cap attaches, and one at the bottom that is a larger hose.  Is yours the same, if so what hose is leaking.

Personally I would not be driving this if it was leaking, if it were to loose more coolant you could be stranded on the side of the road if the engine derates or stand a chance damaging your engine if it didn't derate.

It appears to be the drain hose.   I will be checking in more this morning. 

[Dr4Film]

Well, I am officially confused! 😵

Is there a leak or isn't there a leak?

Aqua-Hot Heater Hose is a separate coolant system that is NOT connected to the engine. UNLESS you are talking about the Aqua-Hot Engine Pre-Heat Hose which uses engine coolant to circulate through its isolated loop inside the Aqua-Hot boiler.

Engine Coolant Recovery Tank overflows, low coolant warning alarms when engine is cold?

Photos and specific information would help to solve this problem as this is not rocket science especially on an Executive.

[JSSangalli]

I had that problem on an M11 engine. It used about a gallon and a half every time I used it. Changed the overflow reservoir cap,  reservoir and everything several different service centers could imagine. Cummins in Tampa put it on the Dyno. There was a leak in the head gasket that would push the coolant out the cap. They changed the head gasket, no more problem.

[Ivan K]

2 hours ago, JSSangalli said:

I had that problem on an M11 engine. It used about a gallon and a half every time I used it. Changed the overflow reservoir cap,  reservoir and everything several different service centers could imagine. Cummins in Tampa put it on the Dyno. There was a leak in the head gasket that would push the coolant out the cap. They changed the head gasket, no more problem.

Yeah, hope this is not the case but that's why I mentioned bubbling in coolant. There are test kits to detect exhaust gas in coolant. Eventually the coolant can push into cylinders and down into oil if that happens.

[JSSangalli]

The chemical was how he confirmed his suspicions. Luckily no coolant got into into the crankcase. It had to be under load to create proper conditions therefore the Dyno. I left Hutchison, KA for Lake Placid, FL, stayed overnight in MS, added about 11/2 gal water next morning, stayed at Wildwood, FL, same amount, 70 miles to Lake Placid, same. I was concerned it would dilute the additive in the coolant and damage the liners, the mechanic wasn't.  I don't remember the low level alarm ever sounding at highway speed but slow down for any reason and it would drive me nuts. I suspect the few degrees of temperature drop or lack of turbulence allowed the water to settle below the sensor.