Coolant leak somewhere near the passenger side firewall. If I can rule out that nipple on the line that goes under the intake manifold, I assume it's probably where the quick connects attach to the heater core lines? Is it possible for the T-fittings to leak that split off for the rear heater?

I looked up the replacement hose set ups, and it looks like they don't come with the quick connects or the metal crimping. So I assume that I would have to use a worm gear hose clamp to attach the quick connects?

If that's the case, can I save myself from buying $120 in OEM style hose kits and just buy 10ft of hose, two t-fittings, and a bunch of hose clamps and just build the same set up for $30 and just clamp it all together? If I do, I think I might leave the quick connects out of the equation as well and just clamp it all right to the hard lines.

I also read something about a flow reducer in one of the lines? Is this something I need to deal with as well?

 

I'm not aware of a flow reducer in the system. As for "old school" hose and clamps, It worked for me. I say "Do it".

 

Something to do with a reducer being installed in the feed line to the heater core to reduce the pressure surge at WOT so the crappy heater core doesn't break at the seam. I guess I'll feel up my hoses and if I don't find one, maybe I don't need one.

I'm thinking it will be easier to just replace both set ups now instead of trying to find the leak.

 

If there is a reducer in there that cannot be reused you can make or buy one from a brass fitting from Home Depot.

 

Is this just something that reduces the diameter or is it a baffle of some kind?

 

I've never heard of a baffle or reducer in the system and as I said earlier, you could just buy a brass fitting and shove it into the hose to reduce the flow. If you don't like the results you can take it back out.

 

Thanks Moto.

Couple more questions since you did this already. Did you clamp everything right to the heater core and the block connections with generic heater hose of the correct diameter? Or did you use the quick connects and hose clamps?

Do you have the rear heat? If so, I assume you used a T-fitting from an auto parts store? Or Lowe's as you mentioned for the brass reducer?

 

I only used the generic hose and clamps in a couple of places that I remember and directly to the heater core itself was one of the places where I used them because I couldn't get the "quick release" OEM clamps off.

 

Do you have the rear heater core?

 

Yes, but my work was all in the front.

 

I understand that, but the hoses come from the front of the block and the rear of the block, and they go to the firewall, but they also have a t-fitting in each one and the bottom part of the T goes to the hard lines from the rear core that come up from under the battery (more or less).

 

In my frustration, I lost my notes on the routing of each coolant hose for the heater cores. For anyone with the rear heater core, which of the lines does the hose coming from the front of the block go to?

 

From my manual, not much info is given.

<TABLE width="95%"><TBODY><TR><TD>SECTION 412-02: Heating/Defrosting
</TD><TD align=right>1998 Expedition/Navigator Workshop Manual
</TD></TR></TBODY></TABLE>
REMOVAL AND INSTALLATION
<HR>Heater Hoses

****** name=tps_proctitle content="Heater Hoses">Removal and Installation

1. Drain the radiator. For additional information, refer to Section 303-03 .

1. Disconnect the heater outlet hose at the engine.

1. Disconnect the heater inlet hose at the engine.
   1. Loosen the hose clamp.
   1. Disconnect the heater inlet hose.

1. Compress the holding tabs and disconnect the heater water hoses (18472) at the heater core (18476).

1. To install, reverse the removal procedure.
   • Lubricate the coolant hoses with MERPOL® meeting Ford specification ESE-M99B144-B or plain water only, if needed.

 

Is there any way to get the pictures that are linked there?