I still have an unidentified leak, and need to get this resolved. It's worse now after having replaced most of the entire cooling system and flushing/refilling with new Rotella ELC coolant.

Original thread where I discussed my new IH water pump and aluminum degas bottle >>> https://www.ford-trucks.com/forums/1...e-trigger.html


BRAND NEW COMPONENTS
IH water pump
OEM style radiator (with plastic heads)
All aluminum degas bottle
Heater bypass valve
Both lower and upper radiator hoses
Degas overflow hose
Degas drain hose
Heater hose (pump to bypass valve)
Heater hose (bypass valve to engine)

REWORKED COMPONENTS
Heater fittings on engine (from core) - removed, cleaned, inspected, found to be sound, reinstalled with new sealant)

COMPONENTS NOT CHANGED
Short stubby hoses from the bypass valve to the heater core (quick connects on the core connection points) - not changed because they are still sturdy and supple with no evidence of leakage.
Thermostat housing was not changed because it is a billet housing in excellent condition with no evidence of warpage or failure.

OBSERVATIONS
Leak is coming from passenger side, up high, near front of engine. The leak is not a major leak, but is a fast drip. Once I park the truck in the driveway and put my catch pan under it, I only capture about 3-6 ounces of coolant between the evening and the next morning.

I can see the cleaned up and reinstalled fitting on the engine, and cannot see any evidence of a leak. There is nothing leaking at the thermostat housing, around the base of the pump, through any of the bolt positions on the pump, from the weep hole, or from any other hose connection. The leak only occurs once the engine is hot and at full operating temperature. I see no evidence of spraying from any pinhole in a hose.

CURRENT PLAN
1) I left the truck at home this morning with a plan to pull out my borescope this evening and snoop around some more in the darker regions I cannot see from above or underneath.
2) Put a socket back on all the bolts to check to make sure I actually got them all tight and that I didn't over-torque one to the point of it breaking when it heated up. This is a highly unlikely set of potential leak points, though, because I can see no evidence that it is coming from those locations. I'll check anyway out of simple due diligence.

QUESTION(s)
1) Where else can I be looking for this leak?
2) Could the brass block fitting be cracked (I just cannot see any evidence that the leak is from that point, but it appears to be very close to that point)?


LINK to Front Cover Life Expectancy Poll >>> https://www.ford-trucks.com/forums/1...xpectancy.html

 

Might have to have someone rev the engine to see the leak.
Any sort of blacklight dyes can be put into the system to assist?

 

Section 303-03: Engine Cooling in the FSM has a lot of ideas and suggestions. I am going to put some screen snips here just in case there is something you have not thought of that may lead you to finding a fix. I have also attached the FSM pinpoint test for identifying a coolant leak.

You suspect the leak is up high on the passenger side, perhaps one of the hoses that runs to and from the heater core has a pinhole in it? What about the 5/8" splice barb that used to be included in the DieselSite kit? I would not suspect the drain plug down by the starter since you believe the leak is up high.

I think using the scope is a good idea and that is how I found my HPO leak which I suspected to be under the T4 pedestal.

The fitting on the passenger side of the pump and pointing toward the headlight, is it dry?

Have you looked closely at the lower radiator hose union to the pump where the clamp is? Is it possible that is slowly leaking?

I helped a friend replace the heater core fittings recently after they started leaking. Perhaps one of yours is leaking and running down the hose a bit to go toward the valve cover.

There is not too much on the passenger side up high other than those hoses, so I would start with a close inspection there.

 

Thanks for those details, Sous. I've printed out the PDF to look through more carefully at lunch.

More detail about where I see the drip... It is running down the side of the block and onto the clamp which holds the loomed start cable, and then dripping off that clamp. See the picture below for reference - the arrow is pointing to exactly the low point where the drip forms and falls.



I don't see evidence of a pinhole in one of the new hoses, but that doesn't mean it's not there. What I DO see on EACH hose, though, is.... well... nothing at all! The hoses are dry from top to bottom and end to end, all while the drip is happening.

I did not use the splice fitting from the kit. Rather, I ran a completely new hose all the way to the bypass valve - no splices.

Both the pump PS nozzle discharge fitting and the hose connection to it are completely dry.

Again, none of the newly installed hoses have any moisture trickles at all (not that I can find, yet?).

As for the heater hose fittings at the heater core, I cannot see any evidence of any leaking there, either. I have felt the bottom side of those hoses, and both are dry. Also, if they were leaking, the oozing leak would most like get doctored off by either or both of the engine bay clamps in which they are placed, and the ooze should either collect in the valley or run down the top side of the valve cover and off the front of the cover to the block (truck is parked on a slight slope with the nose down a bit).

I've carefully looked over the entire new pump, and with it painted blue, it has a shininess which has at times made me think it was wet, but when I touch it, it's dry everywhere I touch - and no red coolant color at all.


All the above is why I'm currently at a complete loss. I still suspect the block fitting, though, because if it has a tiny crack, it could take operating temperature (pressure) to open it enough for a slight ooze. Still, if that really were happening, it really should be worse now after my R&R on that fitting because I really cranked hard on it to make sure it is tight... and it is now much tighter in the block than when I removed it. The brass nipple which connects to it to make it a right angle elbow is just the same -- much tighter now than before, and no visual evidence (yet) of any weepage where the two fitting meet.

 

This is a driver side head the red cjrcle on the right would be where the heater return kine would go, now on the left that's another coolant plug check that one out as well.
the only way you will find your leak is by pressurizing your coolant system. Double check that the new Aluminium bottle isn't the culprit and that your not using the stock pressure clamps.

 

Thanks for the picture.

However, my leak is on the passenger side, and like I've said, every single hose I've replaced is 100% dry both at the hose clamp location, connection to the hose nipples, and down the entire length of the hose. I did choose to re-use the OEM spring pressure hose clamps because there was absolutely no leaking from the hoses before I made these changes, and I'll stand by that decision (for now at least) because all hose connections are still dry.

As for a potential pinhole from the degas bottle...perhaps, and very much worthy of a much closer look.

I'll also look at the PS block drain to see if that may just be the culprit.

 

Heads are identical passenger/driver im just pointing potential leaks.

 

Thanks, Adam. I don't recall ever knowing that there are two drain plugs on each head. It's always good to learn something new!

I assume that one plug is for coolant, and the other for oil?

I will certainly look at those drain plugs this evening.

 

Here's another point of context. Before I changed out my cooling system components, I was not ever building any real "system" pressure because the top of my original OEM degas bottle had cracks and a small hole at the injection seam. No doubt, this allowed whatever is leaking now to have been leaking for quite some time, but it went pretty much unnoticed because the system could not pressurize to make it more obvious.

 

Surely a fellow papermaker has access to paper towels..... Wrap all your hoses and potential leak spots. Run the engine till warm. Locate damp towel covering the leak source

 

Good idea, Wes, but the leak doesn't show up until after I've had the truck on the road for a little drive. I've let it run for as long as 30 minutes in the driveway, occasionally pumping the throttle to give it a little load, and nary a drop will fall.

 

I saw a YouTube video just the other day where a guy used baby powder I think, to find a fuel leak. He just puffed the bottle to give everything a good dusting, then low pressure air to blow away. Powder sticks to wet a leads to source, maybe worth a try.

 

Baby powder is an interesting concept. Before I can do that, I'll have to degrease the engine bay and let it dry, and am willing to consider that if I can't find the leak otherwise.

 

The initial response in Post #2 has the suggestion that I would try first, before baby powder, paper towels (if you can find any, they are being hoarded now) engine de-greasing, or any more guessing.

Coolant compatible fluorescent dye. Cheap blacklight at night. Done.

 

Thanks, Y2K... I needed that head slap!

Listor, sorry for having overlooked your suggestion... it's a good one!

I've located both the dye and flashlight within 5 miles of my house, and will pick them up on the way home tonight.

Did not get to the scope effort last night, but will do that before I use the dye (just in case it becomes obvious with the scope).