Low Coolant Alert

[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.