Leaking Heater Control Valve - Mounted Under the Brake Booster

[2005 Lincoln LS V8]

Hi, it's been a while since my last post.
Has anyone attempted to remove and replace this valve?
If so, did you get to it from the bottom or top?

I can't even see it. I used AI to help diagnose and removed part of the coil cover on the driver's side.

Initially, I thought it was my degas bottle however, I replaced it a few years ago with everything else, Water Pump, Thermostat Housing, Hoses, DCC Valve, Hoses, Radiator etc...

It's clearly leaking right at the bottom of the Power Brake Booster onto an electrical connection. (Bad Design what were they thinking).

When searching online the DCC Valves keep showing up as this is totally different.
the Part Numbers AI came up with:

• Motorcraft: YG‑436
• Ford OEM: 4W4Z‑18495‑AA
• Jaguar OEM: XR8‑2834 (direct interchange)

Thanks

 

[LSV8FAN]

I also have a 2005 LS V8 Ultima that had a coolant leak in the rear engine area that turned out to be a coolant crossover pipe that runs under the intake manifold. It was fixed with some replacement parts from NAPA; below I copied all the part numbers and procedures as stated in the work order.

1 OSP / NAPA 902697 Base
4 *W707299*S300 Ring - Rubber
1 XW4Z*8255*CA Gasket
2 96JV*8255*CB Gasket
2 19549 Antifreeze - Coolant
1 OSP / NAPACrossover Crossover
1 OSP / NAPAMS96923 Intake manifold gasket

Inspect for leak, pressure test. Removed upper intake and replaced coolant passages through engine valley cross over tube, all necessary seals and gaskets. Refill cooling system, purge air and fill to spec. Clean and retest - OK. Road test - OK.

The work was done mid-January 2025. I hope this helps.

 

[2005 Lincoln LS V8]

I also have a 2005 LS V8 Ultima that had a coolant leak in the rear engine area that turned out to be a coolant crossover pipe that runs under the intake manifold. It was fixed with some replacement parts from NAPA; below I copied all the part numbers and procedures as stated in the work order.

1 OSP / NAPA 902697 Base
4 *W707299*S300 Ring - Rubber
1 XW4Z*8255*CA Gasket
2 96JV*8255*CB Gasket
2 19549 Antifreeze - Coolant
1 OSP / NAPACrossover Crossover
1 OSP / NAPAMS96923 Intake manifold gasket

Inspect for leak, pressure test. Removed upper intake and replaced coolant passages through engine valley cross over tube, all necessary seals and gaskets. Refill cooling system, purge air and fill to spec. Clean and retest - OK. Road test - OK.

The work was done mid-January 2025. I hope this helps.

Thanks LSV8FAN,
I've heard about that leak and you have to remove the intake manifold..

The way I found this leak was overfilllimg

 

[2005 Lincoln LS V8]

Thanks LSV8FAN,
I've heard about that leak and you have to remove the intake manifold..

The way I found this leak was by overfilling the system and turning on the engine and the area where you're addressing is all dry...
This one is underneath the power brake booster.
I'll find the description..and will upload

 

[Liquidlounge]

The DCCV is not located in the area that you describing. A leak under the brake booster would most likely be the coolant bottle, the hose connection on the coolant bottle or cap leaking, the bleeder valve, or any of the hoses or connections associated with those parts. If you had the coolant bottle replaced "3 years ago", that would be the first thing that I would suspect as that's a pretty good life on a chinese replacement. On these cars, if you're leaking, you're overheating or vice-versa. If you are running hot from, say from the common thermostat/housing failure - then a lot of the other cooling parts go bad in short order.
T

 

[clubairth]

Again dump AI! It's garbage and this forum has all the information you need. Listen to the guys above. They know these cars!

For better help post some pictures of what your talking about. Hard to figure it out by descriptions.
.
.
.

 

[Pyts]

@Liquidlounge nailed it. The degas bottle and the lower hose that attaches to it are the only potential sources for a coolant leak in that area, and you can see why. Note that goofy metal insert in the bottom port. It's there to add rigidity, and it works, BUT... Dissimilar materials that are mated, which see significant heat fluctuations, will expand and contract at different rates. With like materials, this can cause fusion. Here, it causes separation.

We encounter this all the time with valve cover leaks, yeah?

I ll

 

[2005 Lincoln LS V8]

Clubairth and PYTs,
Thanks for the update!

Yes, AI has taken me way out of line.. It's showing a separate Heater Control Valve mounted under the Brake Master Booster which is wrong! No wonder I can't see it cause it's not there!

I'm going to pull out the Degas Bottle Out and inspect.

FYI I replaced the Degas Bottle 3 Years ago with the Motorcraft OEM Bottle not the aftermarket. (I've seen the posts).

I've seen some aluminum bottles on ebay however, they did not have any kind of sight glass to measure coolant.

Thanks again for the help; I'll circle back when I pull the Bottle out..

View attachment 828582824

 

[2005 Lincoln LS V8]

I'll keep this photo up only for a minut as it's totally wrong!

 

[Pyts]

They got you good with that one! Ain't it the defining lesson of our time -- that it don't matter how true something appears to be.

You're in good company. I'm doing valve cover gaskets, ignition coils and plugs, cleaning plug holes. have to redo the intake manifold gaskets with Mahle brand.. bleh. One of these days SIA will send the PCM back.
The suffering continues. The suffering is infinite.

 

[2005 Lincoln LS V8]

Hey, has anyone purchased an Aluminum Degas Bottle?
I'm looking at this one on Ebay; However, there's no sight glass.

https://ebay.us/m/jOIpTR

If so, how are you keeping up with measuring coolant levels?
By comparing the full mark on the old plastic one and engraving a mark on the Aluminum Degas?

Appreciate any input because I already spent close to $350 three years ago for the Motorcraft OEM.
I see the price nowadays around $200+

Thanks

 

[Pyts]

There's the Uro brand on rockauto.. They make Jag stuff, so it should be up to snuff. I'm gonna get one.

The aluminum reservoir is significantly flawed. It requires taking to an aluminum welder.
I intend to have the work done, but haven't gone through with it yet.. but here's the deal.

The aluminum jug has two spouts up top and one on bottom, same as the plastic tank.
Problem (besides shitty fitment) is that both of the upper tubes are open to the tank. One is just supposed to be a stub to hang the bleed tube on. So that would need to be welded shut.

Next problem: The upper tube that *should* be open has no straw to go down below the coolant level. This effectively fucks the air bleeding procedure because there's nothing to prevent air from being sucked back into the line.

There are also no interior baffles. This isn't the end of the world, but it requires consideration.

I think that if a second port was added to the BOTTOM of the reservoir, the top ports welded shut, and the coolant line that runs to the top port was routed to the new bottom one, that would eliminate the need for a straw while preserving the air check valve principle. Think bongs. Honestly, the straw design is kinda dumb. The only big perk to it that I see is that aggressive driving wouldn't let air back into the straw unless coolant level was below it..
big drawback to the straw design: air doesn't really *want* to come out of it.

On my dorman tank, the straw's not angled enough. I compensate by lifting (in hand) and angling the tank during the bleed procedure.. gets all the air out a hell of a lot faster and more reliably.

Adding a second spout on the bottom of the tank would require some consideration regarding clearance. Everything on this fuckin car is cramped. But you're following the rationale, yeah? There's little alternative if a bulletproof design is what's sought after. You know, shy of having a part actually made *for you* by a shop that will cnc/3d print (or whatever) aluminum

This makes me think though. I wonder if there's another degas bottle that got remade for a different vehicle (presently working on an 05 explorer with the same flaws, but more revised parts).. this reservoir *could* be relocated. No reason it can't except for space.. I'll start checking aftermarket for other vehicles.

 

[Pyts]

Hey. Here's one made by Mishimoto with a sight glass.
Big freakin thing.
amazon listing

This is what it's called:
Mishimoto MMRT-F2D-03P Aluminum Degas Reservoir Tank Fits Ford 6.0 Powerstroke 2003-2007 Polished

 

[Liquidlounge]

That's the same aluminum bottle that I purchased on EBAY 7-8 months ago. Trump must have put a tariff exemption on aluminum coolant bottles because I paid over $85 before the tariffs! Anyway, the aluminum bottle has worked well for me (so far). Once you sort out and understand the cooling systems on these cars, they almost approach dandy. Sure, you will have to cap one of the hose bungs - I just used a rubber cap and a small tension clamp. I also had to take a heat gun and do some minor forming of the inner cowl over the tank. I used to stick my finger into the 2/3 full tank to check, but it hasn't moved. Get a small digital gauge and plug into the OBD port and monitor the temp for a while and you will be driving the car with little anxiety haha

 

[2005 Lincoln LS V8]

Wow, thanks for the updates!
I was thinking that this would be a plug and play deal.

To me, it makes sense for an aluminum degas bottle (only if it's exactly like the plastic oem) because, it's seems like you wouldn't have to think about except if you wanted to clean it out or something..

The LS design approval must have been signed off on a Friday Afternoon! LOL

 

[Pyts]

Yeah.. the problem is the ebay aluminum reservoir is designed to be an overflow tank. Not a degas bottle. Running it will cause air pockets in your cooling system, which will make it more prone to heat stress and associated failures.
What temps do you get running with the aluminum overflow can?

This could be addressed with a swap to a traditional radiator with a radiator cap, and deleting the plumbing going to the degas, to be replaced with an overflow tank.

My above strategy for adding a second port may have some flaws of which I'm unaware, but.. running a reservoir that can't bleed the air out seems like a bad idea to me, conceptually. When I get my shit up and running I'll share my temp readings.

 

[2005 Lincoln LS V8]

Thanks Pyts,
For explaining the difference..
Cause, I was wondering why my 79 Z28 still has the same working coolant reservoir from the factory ..
Hate these new cars!!