Upper Radiator Hose - confused - 1998 4.0 liter SOHC

[Desert_AIP]

I want to replace the radiator hoses on my 1998 XLT with 4.0 liter SOHC engine.
There are clearly four hoses on the engine, but I can only find three by searching.

There is:
Lower Hose, from radiator to water pump.
Motorcraft KM3399
Bypass Hose, from under thermostat housing to engine.
Motorcraft KM3269


Two-piece Upper Hose (this is where I am confused)
There's one piece from the thermostat housing to a metal curved pipe near the alternator.
There's a second piece from the other end of that pipe to the radiator.

When I search, I see "upper radiator hose" only. Not two different parts.
Motorcraft KM3043
Do I cut this hose in the middle?
Or am I searching for the wrong nomenclature?
Does the piece to the engine have a different name than "upper radiator hose"?

Help would be appreciated.
Part numbers would be awesome.

Thanks

 

[RickOTR]

If you have the two piece Radiator hose then do what I did. Delete the metal pipe and order the one piece hose from a 2001 Ford Explorer Sport. It's a perfect fit and you will never have to worry about this again. Ooooh, BTW, the Morotrcraft KM-3399 hose will fit the 97 Explorer as the old part has been discontinued and no longer available. Ebay has a silicone bypass hose for the SOHC engine for $12 including bolts and clamps.

https://rover.ebay.com/rover/1/711-...0001&campid=5574912417&icep_item=233672992586

 

[Desert_AIP]

I confirmed today the KM3043 is just the piece from the radiator to the pipe.

Maybe I'll get the Gen 1 hose above and cut it.
I have to conclude they added the steel pipe for a reason

 

[donalds]

Looks like all the hoses are on rockauto

1998 FORD EXPLORER 4.0L V6 SOHC Radiator Hose | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

And that little hose your looking for

More Information for DAYCO 72022

And the rad hose

More Information for MOTORCRAFT KM3043

 

[Desert_AIP]

Looks like all the hoses are on rockauto

1998 FORD EXPLORER 4.0L V6 SOHC Radiator Hose | RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

And that little hose your looking for

More Information for DAYCO 72022

And the rad hose

More Information for MOTORCRAFT KM3043

Thanks.

Hmmm...no Motorcraft version?

 

[C420sailor]

Just did this job last week. 72022 is indeed the right hose. Comes pre-cut, fits well. Consider doing the heater hose underneath it (thermostat to pipe) while you’re in there.

 

[MakinJeepsWeep!]

My 01 B3000 3.0 I had to order the special T hose for it as well. Some have it some don't some come in two pieces. It all confusing your first time replacing them. Looks like you got it handled though, good luck! Don't forget its antifreeze not water! also would be a good time to flush it out.

 

[Desert_AIP]

Thank guys.

I'll look at the heater hoses too. Looks like two are in that location, an upper a lower.
Can't see where the lower terminates in the engine.
The upper heater hose has a short piece of pipe, then to the firewall (heater core I assume), and another hose coming out of the firewall.

I plan on doing a full system flush before replacing the Thermostat Housing and hoses.

 

[MakinJeepsWeep!]

Probably won't see it until you take it apart. If you don't want to spend much to flush you can use white vinegar its like a 1$ at the dollar store. Slightly acidic so it cleans well. Just flush that out very well too. When I did my 3.0 after I bought it I went through 25 gallons before it was crystal clear but has stayed that way since. Best of luck let us know how it goes. Oh and run your heater to flush heater core as well. Also with flushing there is always the risk of springing a leak if something was near needing to be replaced already just be prepared

 

[donalds]

Thank guys.

I'll look at the heater hoses too. Looks like two are in that location, an upper a lower.
Can't see where the lower terminates in the engine.
The upper heater hose has a short piece of pipe, then to the firewall (heater core I assume), and another hose coming out of the firewall.

I plan on doing a full system flush before replacing the Thermostat Housing and hoses.

What thermostat housing you gonna use

 

[RickOTR]

Those aftermarket hoses don't last to long that's why I always go Motorcraft though they are expensive. As for the bypass and lower heater hose they both attach to the water pump. There's a good chance once you take the metal pipe off you'll see that it is very rusted inside. That's why I opted for the one piece upper radiator hose.

 

[donalds]

Yea my pipe had a little rust not bad tho
I took it off
I then took a coat hanger rod attached a bit of steel wool to it
Put it in my drill and cleaned inside the pipe
Then painted it

I think it's like that to keep the rubber hose off the metal valve cover and alternator

 

[Desert_AIP]

What thermostat housing you gonna use

Simmons Autosportz one piece.

1997-2001 Explorer , ranger, Metal Thermostat Housing (SA20)

 

[MakinJeepsWeep!]

I would expect your never going to get a true seal, coolant also works off pressure, wet metal wet rubber will slip also the metal will expand and contract to some extent with heat and cold. But i totally agree looks awesome! i would run it into the rubber as far as possible and double clamp it and mark the metal at the rubber to see if it is moving out any. Hope it works!!!

 

[DR98FL]

Hi Rick OTR,

Regarding the 4.0 SOHC one piece upper radiator hose up grade you mentioned. I have a 98 Sport SOHC.

Do you have a part # from Rock auto?

It does fit perfectly?

Thanks
DR98

 

[RickOTR]

Hi Rick OTR,

Regarding the 4.0 SOHC one piece upper radiator hose up grade you mentioned. I have a 98 Sport SOHC.

Do you have a part # from Rock auto?

It does fit perfectly?

Thanks
DR98

Here ya go. Explorer and Ranger use the same hose.

NEW Motorcraft Radiator Coolant Hose Upper KM-4791 Ford Ranger 4.0L V6 2001-2011 | eBay

 

[Desert_AIP]

Finally looping back to this project.

Been flushing my cooling system for the past few weeks.
Drained the coolant and added flush chemical and distilled water.
Drove 100 plus miles, drained and refilled with distilled water.

Decided to do the heater hoses too while I have everything apart.
I thought the radiator hoses were confusing until I went down the heater hose rabbit hole.

There are 5 heater hoses in my system, a steel pipe in/out to and from the heater core and a two port heater control valve under the alternator.
Other configurations of this engine and year/gen seem to have only 4 hoses and a 4 port heater control valve mounted closer to the heater core and a longer, more contoured return hose back to the engine.

I think I properly identified everything:
Hose from Tstat housing to pipe going to heater core
Motorcraft KH-578
I can't find that hose in stock anywhere, so I ordered the Dayco 80400

Heater core Inlet
Motorcraft KH-239

Heater core Outlet
Motorcraft KH-634

Outlet pipe to heater control valve
Motorcraft KH-1105
(There's also a KH-203 part but I don't think that's on my config)

Heater control valve to engine return
Motorcraft KH-580

Heater control valve
Motorcraft YG-364

I'm going to replace the steel portion of the upper radiator hose, the elbow piece that's mounted to the engine.
It was over $100, dang, but I bit the bullet.
Motorcraft RH-61

Attached a pic of the old coolant.

 

[Desert_AIP]

Got all 5 heater hoses, the heater control valve, all 3 radiator hoses, the radiator pipe, the bypass hose, the thermostat housing, thermostat and both temperature sensors swapped out, added fresh coolant.
Heater puts out HOT air now.

Flushed the heater core with distilled water before I buttoned everything up.
Hardest part was the dang crankshaft sensor wire that lays across the thermostat housing so tight it's like a strap. It's secured by a bracket with two nuts under the alternator. I finally removed that so I could fold the lead back and it made everything a LOT easer.
I disconnected the battery and the alternator leads as well as removing the throttle body.
Cleaned the MAF and throttle body while I had them off.

Looks like either I have some variant hoses, or they used some substitutes when I had the hoses replaced in 2008. They aren't all the same.

Found a rodent nest behind the thermostat housing in the area under the intake manifold between the valve covers. I have no idea how long that has been there.

 

[Desert_AIP]

Part numbers for those interested.
I used a Motorad fail safe thermostat.