Coolant Loss

[reid9439]

My wife and I just finished a 8,000 mile cross country trip this past November. Our 2005 Presidio made the trip flawlessly. About a month after I winterized the coach, I decided to run up the generator and start the engine. Before the secondary air could build up, the engine shut down because of low coolant. It took 15 quarts of 50/50 antifreeze to fill the system. I'm confused as to where the coolant went. I have never seen any fluid under the engine. Since there is no coolant reservoir installed on the engine there is no way to check the fluid level. There has never been a reservoir installed because the overflow tube runs straight to the bottom of the radiator. I can only assume the fluids are escaping through the "new" radiator cap.

I called Workhorse and inquired why there was no reservoir installed on the chassis. He was clueless and blamed it on the coach builder, Thor.

Has anyone installed an after market reservoir on this type of coach? If so can you provide me with what type, etc.

Here is the info on the coach.

2005 Presidio (Mandalay)

2004 Workhorse chassis with 330HP rear mount Cummins.

[hermanmullins]

Reid,

Good question. Have you checked your oil dip stick for signs of water? Since the overflow tube runs down the radiator is there any signs of blowing water/anti freeze? Have your new cap pressure checked. Is it the correct psi? If you have a rear Radiator lift up the cover and check for water. How has the temp. been while driving? Did the engine start after you refilled the radiator?

I know you have been through all of this but water missing and no sign of leaks is indeed strange.

Good luck, let us know what you find, everyone benifits from all solutions.

[rorr1821]

Could it be you have always been low on coolant and over time you just lost more through evaporation and expansion until you reached a point where the engine got too hot?

Regardless, you have two problems as I see it. First you need a way to check your coolant level and a overflow reservoir tank would probably be the best solution. You also need to check every coolant hose connection and be sure to check in your dash heater area. Coolant has a very defined smell which may help in your search.

As pointed out by another person you need to check your engine oil for coolant. If you find coolant in the oil you need to contact the engine manufacture.

I would be asking the motorhome manufacture tech support why there is no coolant reservoir and how are you going to check for correct coolant level? When an engine gets hot the coolant is going to expand and its got to go somewhere.

Installation of a coolant reservoir would not be difficult once you locate a place to put it. Also after you figure all this out I would consider doing a complete coolant flush. If you call Cummins Fleetguard Division they can advise you on types of coolant and the correct test procedures to check for PH levels, and etc.

[vtbigdog]

You may also have coolant loss as a result of a head gasket leak between the coolant jacket and a cylinder. This would result in coolant being expelled form the exhaust, albeit in a very small quantity If you tow a toad, see if there is a film on the vehicle.

[garykd]

Hi reid9439,

My assumption is the leak is present when the engine is at operating temperature and when cold. This may be a dumb question but what is the coach parked on? I ask because a small coolant leak may drain quite a bit of coolant, over time. If the coach is parked on dirt, gravel or grass,how would you know if there was a small leak? Next on the list is to determine where the low coolant sensor is located. If there is a leak, it will be at a level below this sensor.

I do not feel the radiator cap is to blame. If the radiator cap is to blame, the coolant would need to have been lost on your recent trip. If one was to take off the radiator cap and run the engine, I doubt 15 gallons of coolant could be lost.

[Jon796]

You can also purchase dye that goes into the coolant. Let it run for a while and use a black light. The area of any leak will glow, making it easy to find.

[cmarq]

You say "new" radiator cap. If it was recently replaced is it the right pressure? Coolant comes out the overflow tube when the pressure cap lifts or vents if pressure in the radiator exceeds the rating. A cap for a overflow bottle will be different, they allow coolant to be expelled into the bottle but they also allow it to be sucked back into the radiator when it cools and pressure drops. If it is a replacement cap start there.

Checking the dipstick for coolant is in accurate. The only sign may be the oil level high. If you can remove the oil fill cap on the valve cover or tube and look for a white gel-type substance or you may see it at the end of the engine blowby tube or slobber tube as everyone wants to call it. The coolant turns to steam when the engine is working and condenses on the valve cover when it cools.

If it is present do not run the engine. Antifreeze will take out bearings very quickly. Another way is the remove the dipstick touch the end with the tip off your finger and then touch the end of your tongue, this sounds gross but you only need to have your finger damp, if antifreeze is present it will have a very sweet taste. I spent 40 years with Cummins and we used this as a quick check.

[reid9439]

Thanks for the responses.

I had a mechanic to pressurize the system to the 16 pounds per the pressure cap. Thank goodness the leaks are coming from 2 hose clamps and a gasket on the block. Seems like an easy fix if we don't have trouble finding the gasket. Of course we can always make a gasket if necessary. I'm glad I started now, so I can head to Perry, GA for the rally.

In response to an earlier reply, Workhorse doesn't have a clue why there is no reservoir in the cooling system. They kind of blamed it on Thor. They said sometimes the coach company has to remove them because of the configuration of building the coach. I don't know. There is plenty of room so I will probably add one myself.

Has anyone had to install an after market on this model coach? Any recommendations on the type of reservoir?

[garykd]

Hi reid9439,

Thanks for the solution. It is great when we can all learn from each other.