It has taken me a long time to get to this point. Mostly because I had back up transportation. But it is time. (2001 F150 4.6L Triton V8)

Some time back, under the belief that the problem was the intake gasket, I pulled the top end of the engine down to the heads, cleaned the surfaces, changed the gaskets and put it all back together. (Along the way found that the little piece of rubber hose at the PCV valve had a hole in it. Replaced that) The engine runs better than it ever has. I even lost the lean codes on the OBD II. But..... it still leaked... same way.

I'm too big to get up in there good. But a friend of my son's shinnied his way up in there while it was running, and says it is coming from that little black tube (I have never been able to find it's correct name documented anywhere... even on AlldataDIY!). I hated the idea of going back in to the engine... so I read here where someone repaired it by slipping heater hose on to the black tube far enough to cover the leak and put clamps at each end. PROBLEM: There are two bolting tabs welded on to that tube up behind the passenger side head. You cant slide a hose past those.

I fell down.....(philosophically) and tried a bottle of the Bars Leaks (the silver glitter looking stuff) just yesterday (4/6/12). Well... it slowed it down....but it did NOT stop it. It used to be a fairly fast trickle.... now it a fairly slow trickle. I actually drove it around the block for about 13 - 15 laps then drove about 1 1/2 miles away and back... and still, no seal.

So, I went out this morning... to see if the o vernight sit had anything to do with closing up the leak..... no luck. I topped the coolant tank off ( I can still see Bars Leaks in the coolant!) and am running it.... but so far... no change in the leak condition.

I guess.... that I am just going to HAVE to tear the top of the engine off. It wasn't bad work.... and I guess I did it right...because it REALLY runs good.... no codes. But THIS leads to today's question.

Whatever that little black tube is that goes from the back of the water pump, out the back of the engine....bends up to the passenger's side... and the rear heater hose goes on it (if you have the name I'd love to hear it!)........ how do you get it off at the water pump end??? It almost looks like a black metal band of some kind. It looks as if that is driven onto the tube... then driven onto the back of the water pump area. When I was in there months ago... I gave that tube a wiggle and it did NOT want to move at ALL! Can someone give me an idea how that tube comes off of there?

As always, thanks in advance!

Bob

 

Are you talking about the hose that hooks onto the back of the intake manifold? I can remember on my 2001 Mustang that had a 4.6 it broke off one day while driving. It broke the nipple off the intake somehow, so I had to replace the intake and that fixed it.

It shot coolant all over when it did it.

 

second photo down shows the tube on a 5.4 motor.... good luck.

https://www.ford-trucks.com/forums/8...d-on-5-4l.html

 

Cory, I know that there is a fitting on top of the manifold that the PCV valve tube hooks up to with a big rubber boot. If that is what you are talking about, nope that's not the one. After you remove the intake manifold from the engine and have it down to the heads and the empty valley there is a skinny little tube that attaches right behind the water pump (at the front of the valley) and runs over close to the inside of the passenger side cylinder head, goes out at the back of the head and bend up to the the right (passenger side) and that is where the heater hose clamps one.

Steve's picture (2nd one like he says) shows the tube in all it's glory. The skinny little tube sneaking back through the valley to the back of the engine.

I've seen it before..... I've had my hands on mine.... I just can't figure out how that tube comes off of the inside of the water pump area in the block.

If anyone can tell me I'd love to hear it......

 

I have some info for the 1997 4.6L.

I wanted to change out ALL the heater and coolant hoses, wherever they may be. But I found an odd reference somewhere to a hose INSIDE the V, at the end of the heater return tube, going to the back of the water pump, under the intake manifold!
I looked through my 1997 shop manual, and finally found it under "removing cylinder head while in vehicle". Sure enough, they showed it had a length of hose integral with the front end of the heater return tube. But I also found on some parts sites, mention of a return tube, WITHOUT a hose connection to the back of the water pump area, like an all-tube solution, no hose involved... so which did I really have?
Pull the intake manifold and find out? Yuck no!

I ended up fishing a small light bulb down under the intake manifold from the passengers side, and carefully using an inspection mirror. I was finally able to verify that mine was all tube, no hose on the water pump end.

In trying to order up all of the hoses needed, including the heater hoses with the quick-connect fittings, I ended up with a Motorcraft KH-601, which was the heater return tube with attached hose, the part under the manifold that I didn't need! (but was shown in my shop manual)

Here is a parts callout for that part:
18472 (KH-601)
HVAC Heater Hose
4.6L; includes small hose that attaches to 8555 water bypass tube; Tube asy - Heater return

Not that I needed one because mine doesn't leak, but I found that the ALL-TUBE heater return tube for a 1997 4.6L is the Motorcraft KT-4, here is a parts callout for it:

18663 (KT-4)
HVAC Heater Hose
4.6L,less water port; Attaches to back side of water pump under intake manifold. Slides onto the 8555. O-rings are W704593-S100. (For tube with attaching small hose, refer to 18472).

Yeah, they called it a hose, but its a steel tube. The "18663" is the generic Ford part #, other digits are added to make it specific, which is not shown. But note the "slides onto the 8555". The 8555 is the Ford generic for the tube that goes into the block behind the water pump.

Both of these were found at fordparts.com -> HVAC->Hoses and pipes

For the part behind the water pump, at ->Cooling->Hoses and pipes, there is the part that goes into the block behind the water pump. Again, the number 8555 shown is a Ford Generic for a tube fitting, but this sounds like the one for my ALL-Tube setup:

8555
Water Pump By-Pass Tube
4.6L; Pressed in block behind water pump,both o-rings are W704593-S100; Tube asy - heater water pump inlet tube

So... are there O-rings between those tubes as they slide together?

If there ARE O-rings, then the fastening of the heater return tube to the back of the cylinder head with the two bolts through the integral bracket on the tube, would stop the tube assembly from backing off the fitting while in use.

A few minutes in-person at a Ford parts dept. where you could see the display would be of help to confirm.

There may be changes from my 1997 to your 2001, but the concept is probably the same. Please let us know what you find out!

For anyone interested, I got all of the hoses I needed from Rockauto, an FTE sponsor. All but one. They only listed ONE of the Motorcraft heater hoses to firewall with integral Quick-connect. I saw something else under "heater hose assembly", and thought that could be the missing second hose, so I ordered it up... Wrong! It turned out to be the Motorcraft KH-601 mentioned above, which I don't need nor does it fit. I ended up using my favorite on-line discount Ford dealer and got the correct second heater hose I needed.

EDIT: A thanks to steve(ill) for the ONLY PIC I have ever seen of a heater return tube on the modular engine.

 

I also have a rear water problem, but my solution has not been as easily found.

I began losing water from near the rear of my engine. I assumed it was the heater core, so I took a day and a half and replaced a perfectly good heater core. The water loss continued.

Then I found water behind the alternator in the V under the intake manifold. I purchased a new water pump, then when researching the best procedure to access the water pump, found this forum and read all about the cracked plastic intake manifold problem. Thinking this was it, I purchased the replacement Dorman manifold, new plugs and coils, and dismantled the beast.

When I got the manifold off, I did find a place where it appeared was cracked and with confidence I reassembled the engine, with new water pump, serpentine belt, coils, plugs, etc.

I haven't even cranked it yet. I was filling the block with antifreeze through the thermostat housing opening in the intake manifold when I started hearing splashing. Looking under the truck, I could see water splashing between the engine and transmission. This just occurred last night. In the dark. I cannot access the area close enough to see where it is coming from. Does anyone have a clue?

Is there a freeze plug on the rear of the block? Could I have a cracked block? The truck ran strong and fine before the initial leak was noticed. My hope of course is that I missed something really easy and really stupid. Please give me some ideas.

When the sun comes up again, I am going to try to track it down. But I fear all my work has been for nothing. Going to try to get a camera down back there to see if I can get a better view.

Thanks in advance. I really enjoy reading the problems and the fixes you guys come up with. I am really hoping I can get my truck back.

cdlynes

 

I am adding a link to this post for pictures and p/n of a 4.6 bypass tube replacement ... Google brings this post up

https://www.ford-trucks.com/forums/1...l#post14489264

 

Most of his data applies to 5.4 also. The wire nut on the bolt stud is 10 mm and can be reached with a wrench when intake is off, the tube is held by a 13 mm and I could not find a ratchet / socket combo that worked. Either to short a socket to put a ratchet over wire stud or too long to fit in there. Nuts are behind the tube itself so awkward. Found a Milwaukee socket that has flats and is medium length. Used a wrench on flat socket and started bolt. Fingered out after that. Bought a 1/4 drive as I believe the ratchet would have worked before hitting firewall. The orings are a ridiculous price but old were flat sided.. glad I bought. Used lapping compound to clean up the rust on the water pump end. going to add a little sealant on the stub as well as the new orings. Milwaukee 45-34-8051. Why not designed like that before ?