Explain a "Cold Leak" - Tow Vehicle

[outlawbusa]

Ford Excursion Diesel 6.0

I had a coolant fluid leak early last year that seemed to stop to some extend during the Summer months. This leak has returned now when the temps outside cooled down...which makes me think it has something to do with the heating system or core.

Funny thing though, it only seems to leak when the vehicle is cold. No fluid appears inside the vehicle or floor boards. I let it warm up and build up pressure and no leak. I did a pressure test using a professional system and no leak detected. Doesn't even lose any pressure on the guage if I let it sit there for a while.

Come out the next morning and it's leaking a visable drip drip out of the bottom, but the couple times I've seen it leaking it's been early and 16 degrees out and no time to pop the hood to investigate.

The vehicle has 3 heater controls (3 row seating) and I've tried different combinations using the heaters...I'm thinking it may have two heater cores in it.

The leak is coming from the right side of the engine compartment (looking out the windshield from the drivers seat) and right in front of the fire wall somewhere, dripping down onto the sway bar.

I'm going to attempt another pressure test tonight after it sits a couple hours...

What do you think~?~

 

[aussiekeeper]

I have a 6.0 also. The truck is the same as the SUV as far as front clip components. The heater core for the main cabin is at the R-F firewall. If the SUV has a rear heater core, it will be connected to the engine supply hose near the main core. Some of the hoses are high pressure type, (kinda look like power steering hoses) they will have steel or aluminum ends on them. Sometimes they will leak and then stop leaking. Best thing to do, is to pressure test them by adding pressure to the return bottle on the left side. Just don't apply too much pressure, some of the return lines are held on w/spring clips only. Ford advises to replace the hoses every 5 years or so. If it is a high mileage unit, it may be time to do just that. To make things easier, clean the engine and surrounding area first, but do not use steam or high pressure, one of the computers is mounted on the left top of the engine and there are LOTS of connectors under there, so, hand spray with a hose only. I clean my engine every time I wash the truck, so mine is like new under there.............

 

[Busa1166]

Check the overflow bottle for cracks maybe???

 

[outlawbusa]

I can see it coming down the back of the engine and over the starter with a pretty steady leak, keep in mind it hasn't been run for about 3 hours now...on the oposite side of the plastic container...

it does appear to be coming from above the engine somewhere, but when looking/feeling around the hoses above the engine I do not see any moisture at all.

I'm sure it's in one of these high pressure hoses but just haven't located it yet~!~


I'm curious why this would only leak once cooled down, like something is expanding and sealing when it gets warm.

 

[shadetree57]

pressure test it cold and you'll probably find it. Sometimes we have to let them sit overnight to find them. Cold weather is tough on seals and such. Good luck.

 

[Mr Brown]

Could it be a seal that is contracting when cold? Air brake lines on my mixer truck will bleed air when the motor is off if the temperature is cool, but will hold when its warm.

 

[ogre]

can you find the top of the leak? mirror on a stick and a flashlight does wonders for this kind of stuff.

 

[shadetree57]

Could it be a seal that is contracting when cold? Air brake lines on my mixer truck will bleed air when the motor is off if the temperature is cool, but will hold when its warm.

You bet it could, Cold makes a lot of things draw up.

 

[outlawbusa]

I believe I found it. It was leaking on top of the engine then draining down the back and looks like it might be an easy fix if I cut the old hose off and am able to slide a new one on without having to remove the turbo.

On my way to the store now to see if I can locate a new hose. (The red one)

I don't see this hose in the shop manual...anyone happen to know what it's called~?~

 

[aussiekeeper]

There is an internal oil cooler in the engine valley. That looks like the coolant hose for it. You will need to remove the turbo to change it. While you are at it, take the time to replace all of the hoses.

 

[outlawbusa]

Went by the dealership this morning...(definitely not an Advance Auto part this time)...and it's an EGR coolant hose. $40 bucks

The parts dept could not tell me what kind of crimper I use for the ends (I didn't have enough time to run over to the service dept), anyone got a name and/or a pic of this tool?

 

[Casperle]

There s no tool to put it on it is just a slip fit. Youll have too take the turbo off for access. Cut the old one in half. Pull off in two peices. Twist the front piece too remove it. Put the new on on the cooler first then the front and twist then presure test it.

 

[shadetree57]

Put some slickum on your orings and it'll be a lot easier to install. I use dielectric grease.

 

[outlawbusa]

Cool, thanks for all the advice~!~

 

[ogre]

glad it's figured out bro. time for a chip

 

[proud dad]

Cold water leaks has always been a problem with diesels.Affects the bigger trucks more than pickups.That looks to be Ford's answer to expand and retract of the hose,to stop cold water leaks.Even though the smaller engines don't have as much the problem.Internation engine....Ford designs the fuel system and turbo set up.

 

[Mr Bogus]

dang pretty high tech hose huh? never seen one myself like that... good luck

 

[outlawbusa]

glad it's figured out bro. time for a chip

Already taken care of...with a 4inch SS exhaust to allow the EGT's to escape.

Reads some pretty nasty HP and torque numbers~!~

dang pretty high tech hose huh? never seen one myself like that... good luck

This thing looks incredible. Two layer hose, blue on outside and orange on inside. O rings in ends. Metal cap.

I'm going to tackle it tomorrow in case I run into issues with the turbo.

 

[Mr Bogus]

Already taken care of...with a 4inch SS exhaust to allow the EGT's to escape.

Reads some pretty nasty HP and torque numbers~!~



This thing looks incredible. Two layer hose, blue on outside and orange on inside. O rings in ends. Metal cap.

I'm going to tackle it tomorrow in case I run into issues with the turbo.

looks like one of those "assembly line" miracles that takes all the error factor out of the workers hands.. RacerV has one of those Dodge Diesels on steroids..