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dshogman · 10-16-2007, 11:45 AM

Today I finally got the Low Coolant Level fault properly diagnosed and fixed. For the past few months, the fault has driven me nuts. Had the sensor replaced and still the fault. And all the time the level of the coolant was about 1/4 to 1/3 of the sight glass. Looked OK to me.....
Cummins Harrisburg PA did a complete update of the computer (I was with update 06 and they brought me up to 26). One of the updates was to fix the Low Coolant Level recurring fault. After this they started it up and the fault occurred again. So we're all standing around scratching our heads when one of the techs decides to top off the coolant - first one gallon. Again the sight glass didn't change - so we looked into the tank and it was empty!!!!
Pulled the sight glass and, yes indeed, there was a little coolant in there, but none in the tank. Took just over 4 gallons. Yes, the Low Coolant Level sensor was working correctly.
In looking at the tank, we noticed that it is mounted with a slight tilt to the rear, with the sight glass tilted even a bit more as it stands out from the tank. Hence the reason why the sight glass retained liquid.
Why didn't I check this before, why didn't they check it when the sensor was replaced, why, why, why?
So, be aware.....
I now will make sure the sight glass is always covered.

dshogman · 10-16-2007, 11:45 AM

Today I finally got the Low Coolant Level fault properly diagnosed and fixed. For the past few months, the fault has driven me nuts. Had the sensor replaced and still the fault. And all the time the level of the coolant was about 1/4 to 1/3 of the sight glass. Looked OK to me.....
Cummins Harrisburg PA did a complete update of the computer (I was with update 06 and they brought me up to 26). One of the updates was to fix the Low Coolant Level recurring fault. After this they started it up and the fault occurred again. So we're all standing around scratching our heads when one of the techs decides to top off the coolant - first one gallon. Again the sight glass didn't change - so we looked into the tank and it was empty!!!!
Pulled the sight glass and, yes indeed, there was a little coolant in there, but none in the tank. Took just over 4 gallons. Yes, the Low Coolant Level sensor was working correctly.
In looking at the tank, we noticed that it is mounted with a slight tilt to the rear, with the sight glass tilted even a bit more as it stands out from the tank. Hence the reason why the sight glass retained liquid.
Why didn't I check this before, why didn't they check it when the sensor was replaced, why, why, why?
So, be aware.....
I now will make sure the sight glass is always covered.

hrhuggie · 10-16-2007, 01:39 PM

David,
great piece of information!! I will be checking mine as soon as my engine cools down.

RVRONINPA · 10-16-2007, 03:36 PM

I'm glad you figured it out.I will also make a note of this for future reference. Thanks for the info.

OldForester · 10-16-2007, 07:00 PM

And be sure to check the sight glass when the engine is cold and running. As I posted on an earlier thread, mine is not accurate unless the engine is running. Otherwise it shows empty. If I put coolant into it and bring it 1/2 way up the sight glass when it's showing empty and not running, it overflows when the engine is shut down. But if the engine is cold, running and the coolant is visible 1/2 way up the sight glass, no overflow occurs when I shut the engine down. And the engine stays just fine within temperature.

WeBrzn2 · 10-17-2007, 07:29 AM

Great information! I agree with Oldforester, be very carefull of the engine temp when filling the tank. Mine was recently serviced and has been adjusting itself to the correct level all over my toad!

EngineerMike · 10-18-2007, 11:12 AM

Dave- I'd be most concerned as to why coolant level is so low. You may have the radiator leak that is going around and not know it. Either you never had enough coolant, or it went somewhere.

Rick M · 10-18-2007, 03:02 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dshogman:
So, be aware.....
I now will make sure the sight glass is always covered. </div></BLOCKQUOTE>

Hi Dave

I have noticed that also - so thanks for the tip!
I have seen my radiator reservoir tank overflow after a steep grade and shutting off engine to soon. Be sure to let engine run for 3-5 minutes after stopping to allow engine to cool a little.

EngineerMike · 10-18-2007, 03:16 PM

Our 06 would push coolant out past the sight glass. I put an overflow type cap on the tank and added a plastic jug overflow tank. Then I could fill the tank full up and overflow went into the o-tank while hot, then got sucked back when the system cooled down.

The nice benefit was that normal operation was a full sight glass always, no variables.

APEXMAN · 10-18-2007, 05:54 PM

If you put the over flow hose into a plastic jug it will catch the over flow just like the recovery sys on your car.

dshogman · 10-19-2007, 01:37 PM

EngineerMike - I was also thinking about where the coolant went - so Cummins Harrisburg did a system pressure test. All was OK with the radiator. So I think everyone that looked at the sight glass since I got the coach in April, including me, was deceived and there never was enough coolant in the radiator. The radiator had been replaced by Guaranty before I got the coach as it was leaking. Was it completely filled at that time?? Who knows.....
When I get myself settled in Texas week after next, I'm going to rig the overflow bottle as descibed in the posts.

EngineerMike · 10-20-2007, 12:09 PM

Dave- Couldn't have been never the right coolant level, as it had to get into the sight glass somehow. Could have been the Guaranty guys made same erroneous conclusion on level after replacing radiator. If you always had the low coolant level fault since you owned, I'd say that's it. If the fault appeared some time later, I'd keep watch for a leak. Either way:
1) the jug will help keep an eye on things, and
2) computer has a shutdown for overheat to avoid nuking the engine, and since that was never invoked I wouldn't worry about that.

Louie & Linda · 10-20-2007, 03:39 PM

We have had two Alpines, a 2000 and a 2005. Both had defective radiator caps after about one year. During this time, both used water at a a rate of one gal. per 1000 miles. New caps on both stopped the use of water.

shelland · 10-21-2007, 05:52 AM

Another placed to look for a leak is the heater core above the generator. Mine was seeping and I only noticed it because of a wet spot on the pavement where I parked. I removed the heater core and had it tested and sealed and never had a problem since.

I also had to replace my radiator cap by the way.