Ball valves on coolant lines?

[sbeers]

I have been searching for a coolant leak for some time. I have been adding about 16 ounces to the small plastic overflow tank about every 3-4 trips of about 180 miles each. I have been under the coach front to back many times and cannot find a leak.

I am concerned the engine could be eating coolant, so I plan to add 4 ball valves on coolant lines at the engine. 2 lines going to dash heater, and 2 lines going to Hurricane furnace. This would eliminate a leak in any hose for those systems. I removed both front and rear school bus pumps going to the dash heater some time ago.

I want to ensure this is OK, and will not negatively affect the engine cooling. I would need to shut off all 4 lines for a few trips to see if I will still be losing coolant. Has anyone done this?

[code2e]

Originally Posted by sbeers

I have been searching for a coolant leak for some time. I have been adding about 16 ounces to the small plastic overflow tank about every 3-4 trips of about 180 miles each. I have been under the coach front to back many times and cannot find a leak.

I am concerned the engine could be eating coolant, so I plan to add 4 ball valves on coolant lines at the engine. 2 lines going to dash heater, and 2 lines going to Hurricane furnace. This would eliminate a leak in any hose for those systems. I removed both front and rear school bus pumps going to the dash heater some time ago.

I want to ensure this is OK, and will not negatively affect the engine cooling. I would need to shut off all 4 lines for a few trips to see if I will still be losing coolant. Has anyone done this?

The best way to find coolant leaks is a pressure test. Many large auto parts stores have loaner tools available with refundable deposit. Just ask ablut a radiator pressure test kit.

The tester is a hand pump with pressure gauge and radiator cap adapter. Just pump system up to pressure marked on your radiator cap without engine running. Search around with a good light and also see if pressure holds.

Unfortunately, some leaks are internal. If no drips but pressure is lost, your leak may be internal. Could be engine, could be heater or furnace. If you have a transmission cooler that uses coolant for heat exchange, could be there too.

I do not know if your engine's cooling system depends on those lines as a bypass method, some do. I would not ball valve them shut. Think you will find the pressure test to be a better method.

[sbeers]

Thanks, I do plan to do a pressure test soon. I just had the whole cooling package replaced, so hope it is not there.

[Alpine36]

To answer your question, ball valves should not affect your engine temps whatsoever. Your CC has a robust side radiator, not to worry.
Besides, it’s a good idea to have them anyways in case the heater core or furnace spring a leak. Shut them off, add water and keep going instead of dealing with a roadside breakdown/repair.

Check the radiator cap and make sure you are not overfilling the expansion tank cold.
That can make you chase your tail thinking you have a leak.

[Mark_K5LXP]

Often with these small losses it's the kind of leak that only happens during warmup or cooldown while hoses clamps and fittings are expanding or contracting. In my experience they never get better and over time will leave a sign of some kind, either a crust trail or a moist blob of colored goo. I get nervous about that too but if it was leaking into the engine there would be some pretty conclusive evidence of that inside the oil filler cap ("chocolate mousse"). If it was burning it, that too would have some pretty obvious supporting evidence. I guess you could try and isolate it to a particular subsystem but the end result is you're going to have to track it down visually anyway.

Mark B.
Albuquerque, NM

[TR4]

I put the four valves in about eight years ago, never a problem. If fact, they’re closed most of the time. I put the valves in as a backup. If a dash or Hurricane hose breaks, just shut the valves off. In an emergency, just use your tank water to get you off the road.

Bill

[Roadking]

Had a similar issue traveling in winter snowbird months. Once I was home and rig was parked in garage for a week discovered small pool of antifreeze, a couple of teaspoons, on floor. Traced leak to radiator cores. A year later leak was significant enough to be a concern. I pulled radiator myself which was a pretty big job taking about 6 hours. Took 150 lb aluminum radiator to a shop and it was not repairable. Had a new radiator custom made, big $$$$, and 2 weeks later had rig running. New radiator is awesome. After first trip of 500 miles I lost a couple of quarts of antifreeze and discovered radiator clamps needed to be retorqured after heat cycle. Now all is good. Hopefully your minor leak is discoverable and fixable.

[deandec]

I had a similar problem with coolant loss but no sign of a leak.

Long Story made very short.

I followed the directions for my rig to Burp the air out of the coolant system.

The shop mechanic that changed the coolant failed to do that.

I did the burping and the loss of coolant stopped.

[sbeers]

Thanks for the answer, I will add the valves for the flexibility they provide. I once had a hurricane hose spring a leak on the side of the road and it was a messy afternoon.

I did the pressure test, and found 2 or 3 leaks! The short hose that goes between water pump and oil cooler was dripping away, onto the side of the engine where it would have simply evaporated during use, and a hose fitting on top of a hard pipe in the same area may have been leaking. Tightened the clamps and looks good. I added pics of these. I also found a leak on a heater hose up front. Removed the heater core access panel and tightened all the hose clamps in there. This was leaking intermittently in the past, and now is good.

I also learned my 13 lb. radiator cap is only holding about 8 lbs. pressure. Replaced with new cap. My cooling system drops from 13 to 12 psi over an hour's time. I will try a longer time test to see if it stabilizes.

Alpine36, I have read about the overflow (plastic) tank issue but I am puzzled if the coolant level in that tank goes down, then where does this coolant end up? Does it over fill the aluminum expansion tank? I normally fill it to the cold line and the sight glass is 1/2 covered with coolant in the big tank.

[Old Scout]

What Alpine36 said--expansion tank is just that--it needs room for expansion. It depends on the manufacturer, but I try to keep the coolant that in the middle of site-glass at ops temp, so somewhat below that when cold. My though is if expansion tank is filled properly, an overflow tank really isnt needed--IMHO...

[code2e]

Originally Posted by sbeers

Thanks for the answer, I will add the valves for the flexibility they provide. I once had a hurricane hose spring a leak on the side of the road and it was a messy afternoon.

I did the pressure test, and found 2 or 3 leaks! The short hose that goes between water pump and oil cooler was dripping away, onto the side of the engine where it would have simply evaporated during use, and a hose fitting on top of a hard pipe in the same area may have been leaking. Tightened the clamps and looks good. I added pics of these. I also found a leak on a heater hose up front. Removed the heater core access panel and tightened all the hose clamps in there. This was leaking intermittently in the past, and now is good.

I also learned my 13 lb. radiator cap is only holding about 8 lbs. pressure. Replaced with new cap. My cooling system drops from 13 to 12 psi over an hour's time. I will try a longer time test to see if it stabilizes.

Alpine36, I have read about the overflow (plastic) tank issue but I am puzzled if the coolant level in that tank goes down, then where does this coolant end up? Does it over fill the aluminum expansion tank? I normally fill it to the cold line and the sight glass is 1/2 covered with coolant in the big tank.

I would consider replacing the hose between the water pump and cooler. It has softened some and will give way in time. You can see stretching in the paint cracks. Easy to replace. Notice the longer nipple on the left? Remove old hose and clean nipples well. Just cut a hose to original length, give it a light dab of vaseline and slide it all the way left, then right. Then open clamps and slip over installed hose.

[Alpine36]

Our rig doesn’t have an overflow tank, just a steel expansion tank.
The original sight glass was cloudy, so I was accidentally overfilling it cold.
It’s located in a spot where you can’t see the level with the cap off.
Also had a #13lb cap that was weak like yours. Anyhow, I kept losing coolant. I finally put a temporary jug on the overflow hose, sure enough it was just spitting it out. A new sight glass, #13lb cap and complete flush, haven’t added a drop of coolant in thousands of miles. Well that’s my stupid coolant loss story…
Sounds like your getting a handle on things, good luck.

[sbeers]

Good thought, though accessing that little hose is not easy. I will replace it when I add the ball valves this summer, will need to drain quite a bit of coolant to avoid a huge mess for that job anyhow.

I will also try burping if I see any more loss. Coolant was changed in June with new cooling package install, about 6,000 miles ago at OMC in Oregon. I would hope thy got it right but you never know .

[ArtJoyce]

I would use gate valves. I think of gate valves as more heavy duty to opening and closing after crud has collected on inside.