Good afternoon, first time poster here. I’ve got a 2014 F250 diesel SD with about 180,000 miles on it.

When I came outside this morning, I had a substantial amount of fluid on the driveway kind of under the front passenger side, by the tire. As best I can tell, it’s clear and the viscosity of water. My first thought was it’s condensate from the A/C, but there was more than I typically see, and I hadn’t driven in over 12 hours.

My initial thought - I got home around 6 pm last night. I was running the A/C when driving despite colder temps - I always do this, otherwise the inside fogs up. Overnight, we dipped below freezing for a few hours. Is it possible there was condensate still present that hadn’t dropped off many, many hours later, then froze, then melted this morning when temps were again over freezing? I haven’t seen this before, and like I said, the volume was more than expected. But it seemed to be water rather than coolant, and all of my gauges read fine today when driving.

Thoughts? TIA for any advice.

 

Who knows…..does it have an odor? It’s probably just water.

— Dave

 

No odor that I can detect. Definitely a little greasier to the touch than water though.

Now, 4 hours after I first noticed it, the puddle is still pretty wet on the concrete, even after moving my truck. It’s chilly (46 degrees) but sunny, so it should’ve evaporated if it was just water. And I threw a cup of water down about 30 minutes ago for comparison, and that puddle is mostly dried.

So it’s something else. I guess I should assume it is indeed coolant?

 

Have you topped off the battery lately?

 

Could it have been there before you parked?

 

The battery on that side is brand new, and it was parked overnight in my driveway. Definitely a new puddle.

 

So last night, after the engine had cooled sufficiently, I checked my coolant reservoirs. The primary at the radiator was appropriate but the secondary was so low that I couldn’t read it. I added a half-bottle of Prestone until it was at the upper level of the cold “full” line. I ran the truck idling in the driveway for about 15 minutes - no leak, but the secondary level was no longer visible. I couldn’t find any evidence of a leak under the truck or at any of the hoses.

At this point, I decided to go for a short highway drive. I drove about 35 minutes, until my coolant temp gauge settled in the middle normal range and my engine oil temp was consistently at 195 degrees. I did not run my A/C during this drive.

When I returned home, everything looked great. No leaks that I could see, hoses appeared to be pressurized, etc. The only abnormality was I couldn’t see the coolant level in the secondary reservoir.

This morning, another puddle was present in exactly the same spot, albeit less volume than yesterday. It was dark and I couldn’t see the secondary reservoir, but I assume it’s low still. (I’ll check this afternoon after work.)

So at present, this sounds like there’s a leak somewhere between the secondary reservoir and the water pump, correct?

My only other thought has been a DEF leak, since that fluid is similar to water in consistency, but I haven’t seen any crystallization on the ground that I’d expect, and I can’t imagine any DEF lines around the front passenger tire that might leak in that spot?

 

A lot of the coolant hoses have o-rings to seal them. It could be an o-ring leaking (shrinking) now that the weather is colder and sealing back up after it the engine and coolant heat up to operating temperature. I would pressure test the cooling system when the engine is cold and see if you get any leak down. I have had an o-ring leak when the weather turned cold. It sealed back up when the truck warmed up.

 

That’s a good thought. I’ll look into that. Thank you!

 

Your coolant should be orange in color, right? So if the puddles on the ground is clear why would you think it's coolant?
If you think it's coolant, put a pan or bucket under it to catch it overnight so you can see what color it actually is.
I myself would be looking at a partially clogged condensate drain line if it's leaving a puddle of water after that many hours.
Good luck

 

My initial thought was condensate, but it still hasn’t dried as you’d expect water to. And because of the slope of the driveway, the puddle wasn’t enough to discern a color. I’m not sure what color coolant was in there previously, but I added yellow Prestone last night. It was too dark this morning to tell a color, even with a flashlight. The puddle ran and it just wasn’t deep enough even to soak a little into a paper towel and try to tell. Very frustrating.

 

Crawl under the truck and see where it's leaking from? By the tire it isn't brake fluid? That's clear...

 

I've crawled under as best I can and there’s no obvious leak. Definitely not brake fluid…given the apparent volume that’s down on the concrete, I wouldn’t expect my brakes to have worked yesterday and today.

I'm going to a mechanic today after work and hopefully he’ll find and repair the issue quickly.

 

condensation, no coolant loss wrong color, not brake fluid, no sign of leak. Drive on, concerned turn off the A/C.

 

Place a White sheet under your truck, you’ll be able to identify the fluid much easier that way.