Low Coolant Alert

[michaeldterry]

Two days ago, the owners of Evangeline's new storage home called to ask if I could move the bus to another part of the lot temporarily as they are in the process of running conduit under the concrete tarmac to install an additional 12 Jamestown Advanced 50 Amp power hook-ups! Of course, I had no problem accomodating this request and went right to the bus lot to get Evangeline disconnected from shore power, cranked, warmed up and moved. When I went to crank her - nothing - just a barely audible click. My initial assumption was that I had set the inverters wrong and had allowed the chassis batteries to discharge. However, it had been less than a week since I "exercised" her with a day trip to Forsyth County to watch the indoor drumline that my son designs for and teaches in a competition (and the bus operated flawlessly).

I cranked the generator with no problem, forced the inverters to bulk charge, tried the "battery boost" feature on the dash - all to no avail. On a whim, I went to the back of the bus and opened the engine compartment. I used the rear start panel and she cranked right up! I went back up front and looked at the DDEC only to notice that there was a "Low Coolant Alert" at 0% and the Check Engine (yellow) and Stop Engine (red) lights were both illuminated! I double checked around the exterior of the bus to make sure that there were no "puddles" indicating a coolant/radiator leak. The concrete was dry with no evidence of a prior leak event (no stains). I moved the bus to another part of the lot as requested, but shut her down immediately to make sure that I didn't make things worse. I'm now at a loss for what to do to resolve this latest issue. Obviously, I want to take the bus to an appropriate Detroit Diesel Service Center to have the issue diagnosed/resolved, but I'm scared to drive it any distance with the stop engine light lit!

I'm literally between a rock and a pile of doo-doo! I'm hoping against hope that I simply have a bad sensor, but don't know how to verify that. Is my only recourse a road service call from someone like W.W. Williams? I've got to act on this immediately because we have a hard wired commitment in the bus on April 6th!

Any advice/guidance/help from the POG braintrust will be most appreciated! (Remember to speak slowly and use small words - you're not dealing with the sharpest tool in the drawer)! :o

[garyde]

Hi Michael. Did you check the site glass on your coolant reservoir in the back engine compartment. If it shows full, then your sensor is probaby the culprit. I believe you can wire around it but I don't know if just tieing the sensor wire together will do it.

[truk4u]

Michael,

The inverters have no charge function for the chassis batteries unless Vantare is different then most. Do you have a seperate charger for the chassis batteries? Your chassis batteries were not low, you started it manually. Are you certain the 12 and 24 volt cutoffs in the engine compartment are on. When you got it running with the manual start, did you have the ignition key in the on position? Strange things may happen when starting manually with the ignition on. It almost sounds like the check engine and shut down lights were in the startup test mode that would normally go out as soon as the engine starts. Did you check the site glass on the coolant tank? The low coolant sensor can be bypassed.

[sawdust_128]

Correct. Vantare' did not modify to charge chasssis batteries with inverters.

Michael,

I agree with others, check the coolant level in the expansion tank. It may be that as a result of your last run, you heated the coolant and expanded the volume of coolant into the resevoir. You simultaneously lost some coolant. On cooling, the contraction of the coolant will cause the level to fall below the sight glass and the sensor. I had this happen and it would start, but would only run for seconds and shut down.

Another related question. Last summer when everyone was discussing the bad shape of the coolant lines going to and from the expansion tank, did you check/replace them as well?

[Jon Wehrenberg]

Based on Michael's description the problem may go beyond the coolant level.

I'm just guessing here. The coolant level sensor is the one that can be jumped. Put a paper clip or something between the terminals on the connector and if it is a bad sensor (assuming the coolant is above the sensor probe) that alert should go away. The coolant level sensor is one of the ones that not only shows a check engine, it also will do an engine shut down.

The problem with not being able to start from the front, if not related to the coolant sensor or level could be in the selector switch on the rear box, or at any other switch point within the start circuit including the key switch. To find out the root cause correct the coolant level sensor issue first.

[flyu2there]

Have you pulled the oil dipstick? Should the site glass show coolant I would guess it is some kind of an electrical issue, if it is mt and it is not on the ground.....look at the engine oil quantity.

[Orren Zook]

Michael,

In another thread you mentioned a problem with the keyless entry, the anti-theft portion of that will prevent the bus from starting with the key but will allow engine start from the rear panel, but then, unfortunately most normal "key on" functions won't or don't work - auto leveling, dash gauges, etc. I'd take a look at the relay controlling that first, just because it's easy to do.

[michaeldterry]

Gentlemen - I've accumulated all your helpful replies and will be going out to the bus either this evening or tomorrow morning to follow your collective troubleshooting instructions! I'll let you know what I find and am able to accomplish as soon as I get back. Might I assume that if I see coolant in the sight glass and check the dip stick for level, that jumpering the sensor will enable me to safely move the bus to a qualified Detroit Diesel certified shop to get a resolution (i.e. - replace sensor)?

[Jon Wehrenberg]

The sensor just threads in. If jumpering it solves the problem you can replace it at your leisure. Orren may be on to something.

[michaeldterry]

The sensor just threads in. If jumpering it solves the problem you can replace it at your leisure. Orren may be on to something.

That's encouraging! Here's hoping!!!

[michaeldterry]

Utilizing the replies to this thread, Vita and I went to the bus yesterday determined to get to the bottom of the "Low Coolant Alert" and check engine/stop engine lights. The very first thing we did was locate the sight glass and check it visually. No coolant was visible in the sight glass! We fashioned a make shift "dip stick" and lowered it into the surge tank just to see if there was any coolant at all in the tank. There was a small amount at the bottom of the tank, but it was obviously almost dry. We pulled the Prevost Maintenance Manual in the bus and read up on what we needed to buy to fill the cooling system. Luckily, there was an O'Reilly Auto Parts store right up the street. We went and bought a case (6 gallons) of PEAK Long Life 50/50 Prediluted Antifreeze & Coolant and a funnel. Back to the bus and began refilling the surge tank. It took about 4 1/2 gallons! The good news is that the bus started right up, no alerts - no check engine/stop engine lights!

Lesson learned - I must do a much better and more thorough job of my pre-trip inspections consistently! I've been guilty of giving the pre-trip routine a "lick and a promise" more often than not, just checking what happens to be on my mind at the moment.

I need to construct an organized pre-trip checklist for my bus immediately and commit to using it consistently! If anyone has such a checklist that they are willing to share to get me started, it would be most appreciated!

[garyde]

Hi Michael. there are check lists out there. FMCA offeres one every so often. Each Converter usually has a check list in their manual. One of the things I do is to begin my check list early by several days at least so there are no surprises the day I want to be on the road. I still get surprised sometimes.

[truk4u]

Michael,

Sorry I missed you yesterday, I stopped by about noon and no one was around. Thought I would try to give you hand, but you got it all worked out, so your good to go.

[phorner]

Looks like your low coolant sensor is working and performed its job as designed. If it were mine I would make it my immediate mission to figure out where that coolant went..... and why!

[Mark3101]

Did you ever check your oil as suggested to see if that is where the coolant may have wound up? We had that problem at times with trucks...no leak evident, but losing anti-freeze. Usually it was either a bad head gasket that either let it burn up in the combustion process or a water pump that would leak into the pan (all Caterpillar products mind you). If you can't find an external leak, there is usually something more serious wrong.

[Jon Wehrenberg]

I agree with Mark and suggest being very vigilant regarding coolant loss. If no more is lost it is probable there is not a problem, but if coolant needs to be added often, pray that it is leaking out of a hose because cracked heads, bad head gaskets and other mechanical issues mean some serious money will be spent.

Tips I have learned about coolant. The tank with the sight glass is for expansion. If coolant needs to be added bring the coolant level when cold up to and slightly above the sight glass. If it is filled to the top a lot of coolant will be pushed out when the engine comes up to operating temperature.

Adding 4.5 gallons got my attention. Even if the tank is now filled to capacity I doubt if it holds 4.5 gallons so the coolant level was down quite a bit. Refer back to my first paragraph.

As to coolant type, I hope the correct coolant meeting the applicable Detroit spec has been added. I have yet to see coolant available in automotive stores that meets the spec and to avoid any risk of using the wrong coolant have used the Detroit Diesel products or something available at a truck stop with the Detroit spec. The wrong coolant can lead to plugged radiators or failed cylinder liners. I think the 8V92 is more susceptible to these problems than the Series 60.

[flyu2there]

I don't know what the capacity is from the bottom of the sensor to the bottom of the expansion tank however it is obvious that an amount of coolant equal to that value was lost between the times that you ran the bus. That being said, the coolant went somewhere an apparently it was not onto the ground; even a cup full or so will eventually make it to the floor below the engine. Also there has been lots of discussion about organics and inorganics (coolants) on this forum and one has to be careful not to mix the two less you could end up with Jello in your radiator. As Jon mentioned, the anti freeze should meet the DD Spec which will be posted clearly on the container. I am also in agreement that 4.5 gallons of fluid is a big loss, I would investigate a bit further.

[michaeldterry]

Did you ever check your oil as suggested to see if that is where the coolant may have wound up? We had that problem at times with trucks...no leak evident, but losing anti-freeze. Usually it was either a bad head gasket that either let it burn up in the combustion process or a water pump that would leak into the pan (all Caterpillar products mind you). If you can't find an external leak, there is usually something more serious wrong.

Mark - I did pull the dipstick and it seemed to be registering at an acceptable level. However, beyond looking at the level that the oil reaches on the stick, I'm not certain what else I should look for there to see if coolant has leaked into the oil. How would I know? What would I see? Regardless, i'll be monitoring coolant and oil levels extra closely in the days and weeks to come!

[michaeldterry]

Michael,

Sorry I missed you yesterday, I stopped by about noon and no one was around. Thought I would try to give you hand, but you got it all worked out, so your good to go.

Tom - I'm sorry we missed you, too! We had family Easter obligations at Vita's parents house and had to take an extended mid-day break from our bus adventures to put in the requisite appearance over there! If you would have called my or Vita's cell though, we would have dropped everything and come running! :D

[Mark3101]

Mark - I did pull the dipstick and it seemed to be registering at an acceptable level. However, beyond looking at the level that the oil reaches on the stick, I'm not certain what else I should look for there to see if coolant has leaked into the oil. How would I know? What would I see? Regardless, i'll be monitoring coolant and oil levels extra closely in the days and weeks to come!

Normally, the oil would turn milky in color if there was anti-freeze in it. That was a dead giveaway that something was amiss. Since you put over 4 gallons of coolant in, if it had gone in the oil pan it would be way over full unless you were 4+ gallons low on oil. If I were you, and you are sure there is no external leak, I would take it to a shop and have the cooling system pressure tested to see if the leak can be found. It would be fairly cheap to do and is not too time consuming either. The peace of mind knowing where the coolant went would be worth it I think.....

Also, Jon's thought about having the right type of anti-freeze in the system is also something worth checking. Mixing the wrong type can be bad news as he stated. You could find that out from the tech while getting the system pressure tested if you are not sure yourself from the info on the package. Depending on if a leak is found, you may have to dump all the coolant to fix it and that would be an ideal time to get it right if it is not.

[GDeen]

If one of the hoses to the overflow tank is leaking as the original OEM are prone to do, you could have lost the coolant while traveling and the motor was up to temp - when you shut down in the garage, there may have been just enough left to settle below the sensor low level, but no noticeable leaks on the floor. If this had happened, you should see coolant in the engine compartment though. If it is clean, that theory would be incorrect.

[sawdust_128]

Michael, Good to hear theat you are making progress. Have you checked the lines/hoses going into the expansion tank. If they are original, they are about 15 years old. There were a bunch of folks here who experienced the old hose syndrome on their coaches. What you are describing with "mysterious" coolant loss and failure to start and run is exactly what happens after these hoses have become brittle and cracked. They are pretty well strapped in place so the cracking, altough severe does not get a chance to open up. You don' see the leak because when you stop and shut down to park, everything starts contracting. When you start up, it takes time to warm up enough to start to drive coolant out of the system. Going down the road, the leak is persistent, but slight and the road draft and fan draft dries it. The only way I found mine was I tracked back on a single drop and started pushing the hoses, it then opened up and I could see active leak.



Good luck

[Mark3101]

Michael, Good to hear theat you are making progress. Have you checked the lines/hoses going into the expansion tank. If they are original, they are about 15 years old. There were a bunch of folks here who experienced the old hose syndrome on their coaches. What you are describing with "mysterious" coolant loss and failure to start and run is exactly what happens after these hoses have become brittle and cracked. They are pretty well strapped in place so the cracking, altough severe does not get a chance to open up. You don' see the leak because when you stop and shut down to park, everything starts contracting. When you start up, it takes time to warm up enough to start to drive coolant out of the system. Going down the road, the leak is persistent, but slight and the road draft and fan draft dries it. The only way I found mine was I tracked back on a single drop and started pushing the hoses, it then opened up and I could see active leak.


Good luck

FWIW, I would think that this would be the ideal type of leak that a pressure test could help find. I still think you should have that done as the cost would be small compared to the potential problems that could occur if the leak isn't found and fixed. However, I know it is your money and time, so you should do what you think is right. Let us know what you find. Good luck to you!

[michaeldterry]

FWIW, I would think that this would be the ideal type of leak that a pressure test could help find. I still think you should have that done as the cost would be small compared to the potential problems that could occur if the leak isn't found and fixed. However, I know it is your money and time, so you should do what you think is right. Let us know what you find. Good luck to you!

Would any certified Detroit Diesel shop be qualified to perform the leak test and undertake any needed repairs/adjustments? I have a W.W. Williams shop just over 5 miles from where we store the bus.

[Jon Wehrenberg]

In OKC thanks to Andre and Brian we all learned the three hoses from the coolant tank (the little ones) snap like dried twigs when they age.

If they are not now dripping coolant with the expansion tank full and the bus up to temperature I would suggest getting them replaced. They can be made at any good hose shop, and any competent mechanic can easily replace them. Even if they are not your problem if they have not already been replaced they should be. BTW, touch them at your peril. If they are brittle as suspected they will break.

As to testing the coolant system, any shop can pressurize the system and see if it maintains pressure. If pressure drops then the source of the leak needs to be determined. I suspect Williams will not be looking for leaks inside your coach if that is where they are. They will stay with engine or transmission issues.

[truk4u]

Michael,

I'm not a Williams fan, expecially Kennesaw, but they could do the pressure test. If you have it pressure checked and all is good, I would go ahead and have the coolant changed out. You would then have a base line to go from, have the correct coolant and they could assure the SCA is at the correct level. If the SCA (supplemental coolant additives) is properly maintained, you won't have to worry about corrosion, cavitation, and the formation of deposits, but past sins are anyones guess. You probably have 1 or 2 coolant filters that should have a pre-charge to maintain the proper SCA. I didn't mention
this before since you have your hands full already.

I think you should focus on where 4.5 gallons of coolant went and then go from there. You said you were going out on the 6th and since you have topped off the coolant, see if your losing any during your trip. Remember what Jon said, it's an expansion tank and you want to be sure the coolant is above the site glass when cold.

[Mark3101]

Would any certified Detroit Diesel shop be qualified to perform the leak test and undertake any needed repairs/adjustments? I have a W.W. Williams shop just over 5 miles from where we store the bus.

I have no experience with that dealer, but any DD shop should have no problem doing a cooling system pressure check. They should also be able to fix the problem as well.

[mike kerley]

Michael, I have been caught without spare coolant before (never 4 gallons low, but several quarts) and always added distilled water. May upset the mix, but much safer than adding the wrong chemical mix and being forced to change all of the coolant. May not be the right thing to do, but another idea.

[rahangman]

Concerning the possibility of screwing up the different types of coolant (orange vs green?), what about the coolant that is sold at NAPA which maintains it works with ALL coolants?

[Jon Wehrenberg]

Forget about the color. It means nothing. We learned that in Spearfish.

The only clue to acceptability is if it meets the Detroit spec and it says so on the container. As an alternative it must meet the EC-1 spec for extended life, but that coolant must never be mixed with any other type.

[dale farley]

NAPA sells the Zerex HD ExtendedLife Red antifreeze that meets EC-1 specs. It says it is a 6-year/600K mile antifreeze. The last time I checked, it was $15.06 for the 100% mixture.

[Jon Wehrenberg]

I know there may be an article somewhere or maybe even a thread where coolant was discussed in detail, but for the newer folks to POG who have not had the advantage of the discussion on coolant the simple version is if the coolant lists that it meets the Detroit Diesel specification it is acceptable for use. That coolant should be changed every two years and between changes it should be maintained by the use of conditioning filters which are changed every six months. Those filters meter additives (SCAs) into the coolant to maintain the proper chemistry.

As an alternative, the use of coolant meeting the EC-1 spec, an extended life coolant may be used. The two types of coolant are not compatible, and if EC-1 coolant is to be used, the entire cooling system must be flushed and free of the Detroit spec coolant. The EC-1 coolant is to use a blank cartridge instead of one that adds SCAs, and no coolant except EC-1 spec coolant is to be added to the system.

The EC-1 spec coolant was developed by Caterpillar as an alternative to 2 year coolant changes, and its life is typically expressed as 6 years or 600,000 miles, whichever comes first. Brian is our resident coolant expert having arranged the seminar at Spearfish.

[Mark3101]

Does anybody know if the leak was found or not? Inquiring minds want to know...<g>!

[truk4u]

Dale,

Thanks, that was good news since I haven't been able to find anything locally compatible with my Texaco (Red) Extended Life Coolant. I assume the 100% is the concentrate which is what I'm looking for.

[michaeldterry]

Does anybody know if the leak was found or not? Inquiring minds want to know...<g>!

Not yet. I haven't moved the bus since the incident and have been consumed with other issues. However, my next bus related task is to get it to a Detroit Diesel shop for a leak test, any needed repairs and, if necessary, a coolant flush and refill with an approved brand/rating. I'm hoping to be able to set aside a day early next week to get this accomplished!

[Mark3101]

Not yet. I haven't moved the bus since the incident and have been consumed with other issues. However, my next bus related task is to get it to a Detroit Diesel shop for a leak test, any needed repairs and, if necessary, a coolant flush and refill with an approved brand/rating. I'm hoping to be able to set aside a day early next week to get this accomplished!

I hope you get it all fixed up soon. Keep us posted...we are a curious bunch and want to know all the juicy details! <g>

[truk4u]

Michael,

One question about coolant for you. Do you have an Aquahot heat system or Webasto? Aquahot has it's own coolant tank and Webasto uses the engine coolant. The reason Im asking, is during all that severe weather we had, you had many issues trying to keep things from freezing and if there were prolonged periods of Webasto use, you could have coolant leaks at various places such as cabin heat exchangers, bay heat exchangers, hoses, hot water heater. webasto fittings and engine hose fittings. If you have an Aquahot, then this theory is out the window.

[Mark3101]

Hey Michael, did you ever get to the bottom of the coolant leak?

[michaeldterry]

Hey Michael, did you ever get to the bottom of the coolant leak?

Nothing so far, Mark - but we haven't run the bus much since I refilled the surge tank. The next couple of trips should tell me if i've got a problem or just an isolated "mystery" incident.

[Larry W]

Michael, Here is hoping with the cooler than normal temps in GA this winter your missing coolant was due to cold temps coolant leaks. In the cooler places I have always lived one considers coolant leaks when a rig is setting as part of the game. The first winter we had our coach in CO the coolant level would be low after setting.
Making sure all the hose clamps where tight seems to have been the cure. Tell Vita hello for us.