Separating the water pump

(V12 Dave) #1

So I am re-doing the water pump gaskets and after reading the manual and looking at how fragile the aluminum sections of the pump are, I am stumped on how to separate the two “halves”.
The manual talks about supporting one half and tapping the other through the impeller orifice.
Not sure how one does that. What’s the best practice to separate the two plates?
Also I noticed that most of the bolts have varying degrees of corrosion, to the point where I will have to replace most of them.
Why would this be and how does one prevent it?

Thanks all

(Nigelplug) #2

Separating the lates is not easy! They are held together by two dowels. The way I do it is to tap a Stanley knife blade in between the plates gently to part them.
Once you get them slightly apart, then use a thin screwdriver blade to increase the gap. Using a penetrating fluid is helpful.
The reason they are so tightly held together is often that there is corrosion between the steel dowels and the aluminium plates. Take your time and don’t use too much force.

(V12 Dave) #3

Thanks very much

Do you pry at the bolts or between, and where are the dowels located?

I tried to find them but ran out of time yesterday!



(Nigelplug) #4

Hi Dave
If you have managed to undo all the bolts, they be just be tight in the pump again, due to corrosion. A good soak in penetrating fluid will help.I find if you keep turning them anti clockwise , pulling them at the same time,they normally come out.

The dowels are in the top right,looking from the front of the engine and the bottom left. These two bolts are sometimes more difficult to remove as they are a closer fit,as they pass through the dowels. Again penetrating fluid should help. As is always the case, the longer you can leave them to soak, the better.

(V12 Dave) #5

This is good Nigel, I’ll know where the tight spots are, thanks.

All the bolts came out pretty easily, just a lot of corrosion.

I am wondering what shape the threads in the block are in??

Probably need to be careful reinstalling and torqueing up.

(Nigelplug) #6

Hi Dave
Clean all the threads out with a 5/16”UNC plug tap otherwise known as a third tap. I took a V12 E apart last Friday and some of the bolts were rusted in but the threads were still good think it’s he fact that it’s antifreeze based crud that doesn’t actually seize too bad.

(V12 Dave) #7

The antifreeze thought makes good sense, I’ll look for a plug tap.

Any thoughts on how to avoid the antifreeze from getting into the thread area?

(Nigelplug) #8

I use Wurth grey super silicone it’s both oil and antifreeze resistant.I put a thin covering on all gaskets faces.
This stops water going down into the threads.

(V12 Dave) #9

Hi Nigel, just to confirm you coat both sides of both gaskets, even though the manual says install dry, and you had good luck?

(Nigelplug) #10

Hi Dave
Yes a thin coating on both faces.

Best Regards

Nigel Boycott

(V12 Dave) #11

Thanks Nigel!