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