1998 xlt 5.0 guess this hose/pipe

[Nate_V8]

So i found coolant in the snow last week under my explorer. Didn't notice it until after moving the truck so i tried idling in my parking spot for 20min and rev'd it a few times. No drip and reservoir level was fine so it must be recent. Well I shut it off and left it sitting for 5 days and still no drip but i found this when looking under my truck.

What is that pipe/hose hanging? I wasnt dressed to crawl under and get closer. Could it be where my coolant leak was from?

 

[Turdle]

Looks like the transmission dipstick tube. It has a metal tab on the upper end, should be bolted to the rear of the passenger side cylinder head .

edit, no, I was wrong, on closer look it seems to be the front differential vent tube.
don't rely on reservoir level. Take off the rad cap and check level in radiator.

 

[Nate_V8]

Front diff vent tube eh? Should it be pushed somewhere else? The snow has been high enough to drag on the undercarriage.

Alright I'll the rad, maybe some hard snow pushed on the lower rad hose or something, it was a large drip hole in the snow so I'm surprised I haven't seen anything since

 

[pepehuertars]

It is the front diff vent tube, but if it's leaking, it will be diff fluid and not coolant. Are you sure it's coolant?

The hose must be in upward vertical position over the level of the front differential. I'm not sure if its recommendable to zip tie it or anything like that, the diff moves with the suspension and that will include the hose.

 

[pepehuertars]

btw mine was leaking a bit until I reposition it to the passenger side of the engine bay, but it's as dirty as yours. I'm going to get into this next weekend, maybe removing the hose, cleaning and trying again.

96 ex Front axle / diff vent tube leaking fluid

 

[Nate_V8]

Yea it was definitely coolant, bright green and it wasn't on that side either, it looked to be closer to the front passenger side wheel.

I slipped under the truck today because its now sitting on a sheet of ice, still no drips and I couldn't see anywhere it could be dripping from. While I was under there I propped the vent hose on top of the tranny, I'll see if it comes down again and if it does I just go back with a zip tie.

I checked the rad, completely full, even spurted some coolant out when I opened the cap. My coolant level was near the cold level line so I added a bit of coolant. I'll keep an eye on it now.

What has me scratching my head is that it was a decent amount of coolant in the snow, enough to make a hole a bit bigger than a quarter deep into the snow (snow was up against the undercarriage) but I haven't seen a drip since. I looked around the thermostat housing and dry as a bone, it wasnt the lower rad hose either as that in on the driver side and this leak is more on the passenger side.

 

[Mbrooks420]

It is the front diff vent tube, but if it's leaking, it will be diff fluid and not coolant. Are you sure it's coolant?

The hose must be in upward vertical position over the level of the front differential. I'm not sure if its recommendable to zip tie it or anything like that, the diff moves with the suspension and that will include the hose.

It doesn’t necessarily need to be routed up, and the differential will never move.

I’d check your heater control valve and hosing. It can intermittently leak, and will sometime drip on the manifold and stink, but not leave obvious dripping.

 

[CDW6212R]

That front diff/hose is supposed to be clipped to the front of the left shock tower frame part. It's tough to move that without removing the differential itself. I'd bet the diff was out, and when it went back in, they forgot to route the hose up first, and it's hanging. I doubt it can be put back with the differential in place.

The first picture shows the vent hose hanging down, I removed it from the diff, the first time I had it out of my Mercury.

Then below, I circled the hose mounting clip, in the center of the red, it's barely visible from the outside. You can barely see the white of the plastic vent of the top of the hose, behind the frame edge.

 

[pepehuertars]

That front diff/hose is supposed to be clipped to the front of the left shock tower frame part. It's tough to move that without removing the differential itself. I'd bet the diff was out, and when it went back in, they forgot to route the hose up first, and it's hanging. I doubt it can be put back with the differential in place.

The first picture shows the vent hose hanging down, I removed it from the diff, the first time I had it out of my Mercury.

Then below, I circled the hose mounting clip, in the center of the red, it's barely visible from the outside. You can barely see the white of the plastic vent of the top of the hose, behind the frame edge.

View attachment 167780

View attachment 167781

Great info! thank you very much.

 

[pepehuertars]

Yea it was definitely coolant, bright green and it wasn't on that side either, it looked to be closer to the front passenger side wheel.

I slipped under the truck today because its now sitting on a sheet of ice, still no drips and I couldn't see anywhere it could be dripping from. While I was under there I propped the vent hose on top of the tranny, I'll see if it comes down again and if it does I just go back with a zip tie.

I checked the rad, completely full, even spurted some coolant out when I opened the cap. My coolant level was near the cold level line so I added a bit of coolant. I'll keep an eye on it now.

What has me scratching my head is that it was a decent amount of coolant in the snow, enough to make a hole a bit bigger than a quarter deep into the snow (snow was up against the undercarriage) but I haven't seen a drip since. I looked around the thermostat housing and dry as a bone, it wasnt the lower rad hose either as that in on the driver side and this leak is more on the passenger side.

As someone suggested, maybe check on the heater control valve or heater core, running hot air will make the coolant flow through the valve into the heater core. The heater control valve is made with a very crappy plastic that tends to die rather quickly from the heat cycles.

 

[CDW6212R]

That vent hose has multiple bends to route it up to the left shock area.

 

[Nate_V8]

Well the hose wasn't leaking any fluid like I said and no the diff has not been out of it in the 2-3 years I've had it now lol. We did get 40cm of snow and I had to drive through some deep drifts, perhaps the snow shoved it around? Because I've been under my truck a lot and I would have noticed that hose hanging. It wasn't there when I did my oil change in the fall. Anyways I just shoved it up over the rear of the transmission.
It doesn't need to be sitting a certain way right?


Hmmm check the HCV? Because this may be the problem (99% sure now) because when I idled the truck for 20min and found no leaks I did NOT run the heat and my leak before was on the passenger side before. This would make sense as it looked like a large leak in the snow and then nothing but I didn't run the heat. It's in the engine bay at the top corner on the passenger side right? How hard is it to replace the hcv if it it? I though that would leak inside the truck, not outside (not complaining though lol)

 

[pepehuertars]

Well the hose wasn't leaking any fluid like I said and no the diff has not been out of it in the 2-3 years I've had it now lol. We did get 40cm of snow and I had to drive through some deep drifts, perhaps the snow shoved it around? Because I've been under my truck a lot and I would have noticed that hose hanging. It wasn't there when I did my oil change in the fall. Anyways I just shoved it up over the rear of the transmission.
It doesn't need to be sitting a certain way right?


Hmmm check the HCV? Because this may be the problem (99% sure now) because when I idled the truck for 20min and found no leaks I did NOT run the heat and my leak before was on the passenger side before. This would make sense as it looked like a large leak in the snow and then nothing but I didn't run the heat. It's in the engine bay at the top corner on the passenger side right? How hard is it to replace the hcv if it it? I though that would leak inside the truck, not outside (not complaining though lol)

My truck is a OHV 96, so it might be different in a SOHC, but the heater control valve is on the passenger side and have at least two hoses coming in from the engine and two more going into the firewall (on route to the heater core).

Replacing it is not "a big deal", most of the trouble comes from the fact that the hoses are stuck into the hard plastic of the valve. You can use several technics, for me, just turning them from one side to the other brought them loose. Don't forget to keep track of which hose goes where. You can also use a mechanic's pick to pry the walls of the hose a bit before turning, or using hot water to make them softer while you turn them.

Also silicon spray can help you make the job easier.

A quick google search turns out to show how the valve looks like: 1999 Ford Explorer Replacement Heater Control Valves — CARiD.com

 

[Nate_V8]

Well I really hope it's that, looks easy to replace and cheap. That would be a win for me. Coolant actually goes through that plastic part?

 

[Mbrooks420]

Yeah, it opens and closes to keep hot antifreeze out of the heater core for better AC efficiency.

 

[Nate_V8]

Well I got nothing. 30minutes running, heat on nice and hot, revving up to 3000 (which is overkill because I don't go hgher than 1500 going in and out of my spot). no leak, I found the hpv and it looks slightly different but I turned the heat off and on 15 times and no problem. Not a single drip. So weird

I don't know, maybe someone parked in my spot when I was gone for several days, leaked coolant there, and then I found it the day after I got back when I moved my truck to shovel out my spot.... There is a parking lot **** who parks in any open spot at night, maybe her old pos honda leaks coolant sometimes and she parked in my spot when I was gone....although I don't see any coolant where she usually tries to park but that could mean nothing.