I'm at my end with my Excursion. I have coolant that keep blowing our of the Degas bottle, under the cap. I'm really tired of working on my truck, I'd like to just drive it and enjoy it for a while...

Nov. 25, 2013 - Flushed the system according to the instructions and filled with Cat ELC

Jan 7, 2014 - Noticed coolant leaking out of the degas bottle at the lower hose connection. Replaced bottle with a Dorman Unit.

Early February - Installed coolant filter kit when I noticed a leak at the oil cooler; this is when my constant trouble started.

Through out February I've chased reason why coolant would blow out from under the coolant cap. I replaced with three different FORD caps and finally replaced the bottle with a FORD bottle.

This caused the water pump to start leaking at the weep hole.

Early March - Replaced the water pump with one from RiffRaff. I got an air bubble in the heater core and lost heat. Got that fixed and thought all was good. Coolant level stayed at "COLD MIN" and performed awesome.

Well today, I got out did some running around town. When I pulled over to get diesel, I noticed coolant spary (red) all over the passenger front door. Raised the hood and sure enough, the passenger side battery is covered in coolant. I check the cap and it was tight.

The coolant level is now just below the seam in the Degas bottle.

I'm wishing I had never flushed the coolant system back on Thanksgiving. It's been noting but issues.

I really like the truck, but I've been trying to get the maintance done, but it's always something.

Does anyone have a clue on what to do with the coolant system so I won't loose ELC everytime I dirve?

 

Check the lip on the dorman bottle. Some folks have had trouble getting them to seal because the casting seam, shaving it down seems to help.

 

The dorman was replaced with a ford bottle...

 

I'm assuming there are no obvious leaks? It seems like you got the situation under control before, and today you could've sprung a leak that the fan blew all over the place.

Maybe try spraying everything down with water to make everything clean, then pressurize the system with a pressure tester and look for a leak. Maybe the pump seal failed or something.

 

The water pump is good, the ELC is clearly coming from the FORD cap on the FORD bottle.

Something is causing the pressure to build beyond the 16PSI and forcing it out cap, but not the pressure relief, the threaded lip.

 

Did you replace the thermostat when you did the water pump?

 

You bet, I've replaced everything I can think of except the motor. That's why I'm going bald from pulling my hair out.

 

Wow, I guess I'd be in the same boat as you. It seems you've done everything I would've done. Sorry I can't be of more help

 

When it blows some out, are you adding water to make it up or just leaving it alone?

 

Right now I'm just leaving it alone to see if it happens again. I've been driving around today and keeping a close eye on it.


When it cools it's below the plastic seam in the degas bottle, when it hot it fills up to the 'cold' mark.

I'm at a loss

 

That's exactly where mine settles out. I went through the same thing a long time ago, then I finally gave up on trying to keep it at the cold mark when it was actually cold and it leveled off just as you described.

 

Did you use the short stem or long stem thermostat? I can't remember for sure if the long stem will fit if it is not the correct one. You could even remove the t-stat to make sure that is not the problem.
Something is certainly causing the cooling system to over pressurize and blow out the cap.

Hang in there chief, it's got to be something simple.

 

I bought evething from clay, so I assume it's ford current stock.

 

Not the first time I've heard of that...had a buddy that was driving himself crazy worrying when he finally said to hell with it it settled right where you describe & stays there

 

I just figured out what the thermal expansion of 8 gallons of a 50/50 mix of water and propylene glycol is. Starting at 30F, with a 203F thermostat, when it reaches operating temp. it expands to 8.603 gallons. If it's ethylene glycol, it would be slightly less. If there isn't 0.603 gallons of space in the degas bottle, out it goes. These trucks are one of the few vehicles I've seen that don't use an actual overflow reservoir to catch expelled fluid so it can be drawn back in as the system cools.