Community Forums

RVFunlovers · 03-21-2023, 08:04 PM

I have had to add coolant to my coach three times in the past 6,000 miles.

Not much coolant. About 1.3 gallons total.

I have seen no coolant under my radiator. I have seen a few drops under the back of the coach on the ground. Looks like it would be right under the coolant fill area.

I have seen no leak, drip, active drop, etc…

No change in engine temp at all.

I have been keeping a couple gallons of final charge with me and traveling with plenty of water in my fresh water tank.

How big of a concern is this? Make an appointment with a repair shop ASAP? Or wait until I go to Spartan 7 months from now for regular service?

I am not even sure it is leaking enough to see. But coolant is going somewhere.

When I add coolant I am adding enough to just cover the sight glass.

Coach is still under warranty.

brobox · 03-22-2023, 04:56 AM

Hal, to be safe have a pressure test done on the radiator. It's OK if it's a slow leak that dries before your see it. But if it is leaking into the engine, not good. Is your oil still the same black color?
You can try tightening all of the hoses. On my 14 they were not torqued and I was loosing coolant.

In the old days, auto parts stores would lend pressure testers, but I don't know if they still do. NAPA does have the larger cap sized for trucks. Any truck type shop should be able to do a 5 minute pressure test.

LETMGROW · 03-22-2023, 05:12 AM

Sometimes trying to find a really small coolant leak can be frustrating. They make a "Tracer Dye" which can be added to the coolant which can be seen more easily than just a small amount of coolant at the source of a leak. Some or most of these dyes can be used with an Ultra Violet lamp and the leaked coolant will glow when the light hits it.
Available in most automotive parts stores.

brobox · 03-22-2023, 05:33 AM

Hal, per Cummins, do not add anything foreign to the radiator that could void the Cummins warranty. They are really finicky on what coolant is used and say no additives. Simple air pressure will show where the leak is.

sploke · 03-22-2023, 06:02 AM

Autozone has a loaner kit to pressurize the radiator to check for leaks. It pressure fits into the filler neck and you use compressed air to load it up then wait and check for leakage. Just ensure you're not pressurizing higher than whatever your stock radiator cap is rated for, lest you burst something.

wolfe10 · 03-22-2023, 06:21 AM

I would start by tightening up all the hose clamps.

Particularly in cold temperatures, as metal "shrinks" leaks can occur that are easy to fix.

Constant torque clamps are best. If there is room on the metal over which the hose fits for a second hose clamp, a good idea. Place the screw mechanism 180 degrees from the other clamp.

Bobby Dowdle · 03-22-2023, 07:34 AM

If you are burning coolant and you aren't seeing any, in could be going into the engine. That's a very expensive part and I would recommend having a qualified location pressure test your system. You might need an adapter for the pressure tester. Some of our units require them. Pressurize it up and check to see if you see a drop in the system. If you do, you know you need to get to your servicing dealer or any NIRVC service department. Hal, if you want to get it to us, we can get you an appointment quickly if you reach out to your advisor.

Old Scout · 03-22-2023, 08:09 AM

Curious, what is the protocol for filling your coolant? Most rigs have an expansion tank vs an over-flow tank. This means there has to be room in the tank for the coolant to expand at engine ops temps. So, checking the sight glass when engine is cold and refilling to top of glass might result in and overfill situation where "excess" coolant simply overflows to the ground while underway.
One good place to look for leaks is the in- and out- ports on the engine that feed the dash heater or aqua-hot. Engine heat seems to weaken these hose connections. New clamps or adding a second clamp often helps.

Unplanned Tourist · 03-22-2023, 08:39 AM

Get a oil analysis done ASAP. It could be the coolant is leaking internally.

Look for any counts of glycol in the analysis. If none, then it's safe to just keep topping it up.

Turbojack · 03-22-2023, 09:05 AM

1.3 gallons is a pretty big leak. Do as others have said and get pressure test.

brobox · 03-22-2023, 11:52 AM

Quote:

Originally Posted by Unplanned Tourist

Get a oil analysis done ASAP. It could be the coolant is leaking internally.

Look for any counts of glycol in the analysis. If none, then it's safe to just keep topping it up.

That might be a little overkill for what might be a loose hose clamp on a new coach. Milky color oil would be a sign that there is coolant in the oil. If there is antifreeze in the oil, Spartan and Cummins get to fight it out on who's warranty is going to cover it.

Unplanned Tourist · 03-22-2023, 01:05 PM

Quote:

Originally Posted by brobox

That might be a little overkill for what might be a loose hose clamp on a new coach. Milky color oil would be a sign that there is coolant in the oil. If there is antifreeze in the oil, Spartan and Cummins get to fight it out on who's warranty is going to cover it.

Just sayin' It's his rig, but if it was me, I would spend the $20-30.00 just to have peace of mind. We found traces of glycol when there was absolutely no sign of coolant in the oil. Usually it was the EGR cooler, but could be a very small pin hole in a casting.

At the least you will have a baseline test resut to compare for future tests.

RVFunlovers · 03-22-2023, 07:35 PM

Thanks for the ideas. I worked all day today but I will check my oil level in the next day or two. I checked it about 3,000 miles ago and it was dead on perfect and looked normal. So hopefully no coolant going into the oil.

I am scheduled to drive home from Louisville to Michigan Saturday. I will stop after an hour and let the engine run. I will see if I see any antifreeze. Even a drop or two. If I lose any coolant I will try to get into Spartan. I live close to them. They have been good at working me in when I am in a pinch. I also have a good Cummins shop in Grand Rapids that I can try to get in with.

Maybe this is something minor. I certainly hope it is.

I was just talking about my rate of problems slowing down lately. But I think this started a while ago. 150 oz leaked in about 6,000 miles is about 1.5 oz every 60 miles or every hour or so. Pretty hard to see that rate but maybe the pressure test will detect it.

brobox · 03-23-2023, 05:28 AM

Hal, Also try shutting the engine off. The cooling system will still be under pressure and you can get closer to hoses with a flashlight to better look for leaks. Also the seal on the pressure cap shuld be tested with the pressure tester. It sounds like the cap has been removed several times.