New Water Pump Leaks

Been working as time allows on repairs including replacement of water pump and all coolant hoses. After five months finally got to the stage of refilling coolant system. After topping off the radiator a slow drip started. That was last night. Could not take the disappointment so went to bed. Could not sleep so at 5:30 this morning put my Stant pressure tester on the header tank and at 5 PSIG heard a steady leak. The cars front end is raised on jack stands so crawled under with a flash light and saw the source of the leak being the water pump gasket. This is a paper gasket that came with the new water pump. Did apply a little Loctite 518 to both sides of the back side gasket.
Will not work on repairing this leak until next week and would like to ask if any one has found the Ford improved Garlock gaskets. What a PITA this is becoming.
Also no where in any of the maintenance manuals can I find the recommended torque for the water pump bolts. Being an aluminum block did not get carried away when installing the pump and itt may be that they just aren’t snugged up enough.
Did use a slender 1/2" open end wrench to tighten the hidden bolt behind the belt tensioner assembly.

Feel your pain. The problem is not only the crap gaskets but the ambiguity of what to use as a gasket dressing. My advice is not to use a gasket dressing but an honest gasket maker sealer. In other words don’t worry about how to get that gasket off on the future.

Thanks Bernard for your reply to the leaking gasket problem. Yes will be using a gasket dressing that gets good and hard. If that fails will be using the engine a a boat anchor and swap the V12 Jag for an electric power plant.

Finally removed the leaking water pump early this morning. If you too need to replace your water pump and order a new one do the following before you install it. I did not and the following may be the cause of the leak.
After removing the pump and wiping off the flange faces I placed my 18 inch inspection scale on its edge against the back of the pump. There is a 0.025+ gap in the center. The OEM pump that it replaced is perfectly flat and has zero gaps. In short this aftermarket part is not made to the same standars as the Jaguar original.
I did not mention the fact that this new pump does not have the set screw to secure the bearing in the correct position either. Guess I thought it must be OK since the vendor has sold many of them. Should have trusted my instincts and not the vendor.
Now weihing my options as the pump may not be returnable as I bought it way back in February. If not will order another pump from a different vendor

Just got off the phone with the parts house and they are very understanding. Will be returning the pump tomorrow. To restate there where three things not up to snuff with this pump.
First is the impeller gap was at 0.055" and I had to use an arbor press to correct it to 0.025".
Second : There is no set screw to hold the bearing in place.
And third and worst of all the back side of the pump is warped.
Hope this helps someone.

For what it is worth, the set screw was eliminated in the late 80’s. this way a totally sealed bearing was used instead of one with a hole in the side. A lot of the pumps get warped. We surface the main housing and the larger flat piece will flatten out when torqued down unless it has been ground on. I like to see the impeller gap as small as possible without the chance of scraping. This lets the pump work better. To close and you will get a scraping noise when first cranked up. However, through the magic of a multi blade steel impeller rubbing on aluminum, it will clearance itself rather quickly. Still not the recommended proceedure. The proceedure must work as we have not had any V12 water pump warranties.

Yeah, sounds bad, but I’m still not entirely sure any of that explains your problem. The housing of the V12 water pump has long “wings” on it for the outlets, I could see them being distorted but they’d still bolt down and seal up OK. The lack of a set screw may be distressing, but I dunno how that would make it leak. Same with the impeller gap.

Could you tell if this assembly was leaking at the joint with the timing cover or at the joint between the halves of the pump itself? Were the gaskets paper or gortex?

Leak was at lower left below where the PS pump tensioner bolt attaches.
Gaskets where paper. Have looked and look and looked but never found any vendor on planet earth offering the Gortex gaskets.
As stated earlier I do not have any idea as to t he maximum torque these water pump bolts should have. Was pushing the envelope at 12 to 15 foot pounds. The last thing needed is a stripped thread in the block.
So if any KNOWS what Jaguar says to torque these bolts to let us know.

I’m about to replace my V12 water pump, when removing the old water pump I noticed Black RTV sealant on both sides of the paper gasket. As far as I can tell this pump never leaked, and I will be using the same sealant on the new water pump. I read the following off the web: “The crossover pipe bolt torque is 10-14 Nm (7-10 ft. lbs.), water pump bolts 10 - 14 Nm, and the thermostat bolts 8-10 Nm (6-8 ft. lbs.)”, seems reasonable to me if using RTV.

Thanks for the bolt torque numbers you found. Waiting for another water pump to be delivered this coming week. This one is a rebuilt unit as am wary of these not OEM new pumps. The gaskets being delivered with my new rebuilt pump are said to be AFM material,
After researching what AFM means it seems to be a tear resistant gasket. The vendor is Terry’s Jaguar in Michigan.
On their website the gasket is described as being an Aluminum Formette Material. When looking up the meaning of formette it is a term used in the paper industry. If you get a google response showing a former LSU football player you have to make sure you spell it as formette.
Will let you know what the rebuilt pump looks like when it arrives. Will be checking the impeller quality along with it’s clearance to the front of the pump and that the back is perfectly flat. Attaching picture of the new pumps impeller for you to see the ragged edge of the vanes.

Believe the new pump leaked because the “wings” are distorted back by the 0.025’ mention previously and this caused the the paper gasket to get pinched and tear.
Thanks again Ozbie for your input.

Don, would you mind telling me who you bought the water pump from, I’m seeing similar serrations on my pump from XKs.

That is where the new after market pump was purchased. Called them and explained problems with the pump and they where very understanding and agreed to accept the pump for return and credit if returned in the same box and was as received. However I forgot that to install the pump which did not have the tapered head screw as on the OE, I had filed the front edged flat to insure good compression of the gasket using a hex head bolt and washer.

I don’t have the original box but I’ll make an attempt to return, I have a reliable source out of Toronto that sells OEM grade parts, I should have heeded the warnings, you get what you pay for.

Would you please uses a quality straight edge and check the flatness of the back of the new pump. If the back is flat then it may work for you, but not sure of the gasket it came with.

The impeller on the pump I’m replacing is pristine, very well machined, I don’t want sub par quality, so I’ll attempt to return for refund or eat the cost.

New rebuilt water pump arrived today. Back plate is perfectly flat and impeller looks good.
Gasket looks much better quality

. Hope to install over the next few days and will tell you how it all works out. The impeller gap was set correctly at 0.025". There is no set screw holding the bearing seal but that seems to be they are made now.

Since the rebuilt pump you received meets the standards, would you mind sharing the source?

This rebuilt water pump is from Engel Imports which I first knew of as Terry’s Jaguar. Thier part number is GWP416R.

Dick if you can private message me would like to discuss an A/C muffler purchased from Coventry West back in 2012. It was made wrong and no way will it work on the an A6 compressor.

You show a picture of the green gasket. This is genuine Jaguar but they are brittle and have a tendency to crack when tightened down. I recommend you use the one that came with the pump and put some aviation Form a Gasket on the pump and the timing cover with the gasket in between. The gray colored gasket is about twice as thick as the original thin paper and much more forgiving than the later Jaguar green ones.

Cant seem to get private message to work today. How about e-mailing me