Antifreeze/water leakage

[JRS]

about 5,000 miles ago I replaced the thermostat, water pump, heater hoses, both the small bypass hoses at the front of the engine, and the upper and lower radiator hoses all under the guise of preventative maint. A week ago I started losing coolant, not a lot, but maybe a 1/8"-1/4" every two or three days out of the resevoir. (I drive about the same mileage every day) I check the weep hole on the water pump everday, both when it's cold and when it's hot and pressured up, and nothing. I can't see any evidence of leaking anywhere else. I have checked the heater hoses where they pass through the fire wall, both ends of the radiator hoses, the small bypass hoses, and the passenger floorboard. All are bone dry, both when the engine is cold and when it's hot and pressured up. I can't smell any antifreeze burning (like from a leak getting on a hot manifold or engine) When I installed the water pump I made sure the mating surfaces were hospital clean by prepping the surfaces with a 3-M scotch-brite pad on my die grinder, then wiping them down with a rag and some brake cleaner. I then coated the rubber gasket with a THIN layer of high-temp silicone, let it get tacky for 15 minutes, then installed the water pump and torqued the bolts to the final torque. Is this the correct procedure for installing the pump? should I use any silicone on the rubber gasket? Any other ideas?

 

[lmitchell]

Since you are loosing the coolant out of your reservoir that leads me to believe that you may have a blown head gasket. Try taking off your radiator cap and have someone rev up your engine to about 2000-2200 RPM. Watch for bubbles in your radiator. If you see bubbles, you more than likely have blown a head gasket. Your water loss will continue to get worse, and you will usually end up making a big mess by filling your radiator with engine oil .

 

[Dieselnerd]

Or maybe it's not so bad after all. I had a case of coolant missing a few months ago after I drained and changed it and was as concerned as you are. I researched old posts and tightened every clamp in the system. There are a lot of them! Like you, I smelled no coolant and could find no leaks but after tightening everything up it stopped losing coolant. I don't know if there are places in the cooling system that hold air bubbles or I had a loose clamp but since it never lost any coolant until the day I changed it I assumed it had something to do with the coolant change and I was right. Tighten it all up and give it a little time.

 

[JRS]

just checked, no bubbles in the radiator...

 

[Dieselnerd]

JRS, did you just start using the heater recently? If you didn't run the heater wide open for a while after you changed all your hoses it's possible you had air in there that is now working it's way out. Someone else posted that as a fix for their problem sometime back.

 

[JRS]

Excellent point. I thought about this too, but I have been using the heater in the morning for a week now. I would hope the air would have purged itself by now. What ever it is, it leaks at the same rate. I thought about a slightly leaky radiator cap, but I think the resevoir would overflow and the truck overheat.



Did I install the water pump incorrectly by putting silicone rubber on the gasket? I was very careful on the amount I used, so it didn't spooge out into the water channels.

 

[PUMPERDUDE]

Think its the heater?

"I thought about this too, but I have been using the heater in the morning for a week now"... ... ... ... ... ... ... . "A week ago I started losing coolant, not a lot, but maybe a 1/8"-1/4" every two or three days out of the resevoir. "

I'm not trying to be smart but seems like quite a coincidence . Could have been air in your heating sustem. Could be a leaking core. It could be that the ambient temperature is keeping your truck cooler than it has been lately. This will progressively lower your coolant reserve. I think you have nothing to worry about. Everyone should watch thier trucks as close as you do.

 

[JJW_ND]

It takes quite a while to get all the air out of the sytems. You can speed this up be getting the system good and hot. Need a trailer or something to work the engine, or block the radiator with cardboard. Takes a lot of heat to open the Tstat and keep it open.



I have had a leaky heater core. No mistaken the smell. If you have a TINY leak it will stink you out of the cab.



I also have a head gasket leak. All external (nothing getting inside the engine or oil). Visible by the Tstat housing. Been that way for 80K miles. Even though the leak is very minor (gallon ever 20K) I again can smell it very easy almost every day.



If your not getting bubbles in the coolant..... internal head gasket leak... I would keep adding an watch it for a while.



jjw

ND

 

[redram]

Originally posted by JRS

Excellent point. I thought about this too, but I have been using the heater in the morning for a week now. I would hope the air would have purged itself by now. What ever it is, it leaks at the same rate. I thought about a slightly leaky radiator cap, but I think the resevoir would overflow and the truck overheat.



Did I install the water pump incorrectly by putting silicone rubber on the gasket? I was very careful on the amount I used, so it didn't spooge out into the water channels.

I can not speak for a Cummins Water Pump but in my experiencess with racing and import cars, it is NOT wise to use silicone on a rubber gasket.



Hope this is not your problem.

 

[illflem]

JJW-ND has the best advice, it's just air in the system that needs to be worked out. Most every CTD cooling system I've worked on takes a week or more to eliminate the air, I warn the owners. If your t-stat isn't opening due to colder temps it can take longer.