Water pump choices (XJS V12)

I have for no good reason taken out the properly running water pump from my engine. Why? Because “I was already down there” and thought might as well do some preventative repairs.

Now I am left with two choices:

One, install a Jaguar refurbished unit which I received from a UK vendor.

Two, get a nice new gasket and reinstall mine exactly as it was.

Rebuilding mine is not an option, I dont have the wherewithal.

Why even the choice? The unit I received is slightly different (doesn’t have the countersunk hole) and, more importantly, the pulley doesn’t spin as freely. Which brings me to the crux: should the pulley spin freely, as in coast (almost like an idler), which is what my existing, original, and “properly running” water pump pulley does?

Or should it be smooth but stiff and only turn as much as you manually turn it by hand like the recon/reman/refurb unit I received does?

Apart from that (and the countersunk hole, and the lack of the grease nipple, and what appears like paper gasket in the sandwich), the recon one seems fine.

Legit question or mere paranoia?

Thank you in advance.

New bearings and seals are supposed to feel a bit stiff. I’d countersink that hole and install the refirb.

Thank you Kirby, that’s reassuring. I’ll go ahead and do just that. Now on to getting that tensioner hole plug out!

You may not need the countersink the hole. Look at the clearance to a normal bolthead first. I didn’t need to countersink my new pump.

I am planning on doing exactly this later in the year when I replace my working but original radiator. May as well replace working pump. And i will get a Jaguar water pump rebuilt too. I recommend getting a tensioner hole plug from John John, very well engineered.

Curious, can we get a new gasket that is not paper? Does the pump come with gasket? Do you reuse bolts? Loctite?

You can get the updated gaskets as outlined in The Book. I didn’t reuse the bolts/studs as some were quite rusty. I used antiseize on all of the new bolts and studs, as removing some was quite scary. The last thing you want to do is use locktite as you have steel bolts into aluminum which try to seize up. I didn’t know if they’d come loose or snap off. If some snap off it’s a major issue as the timing cover would have to be removed to drill them out. The bolts/studs are of many different lengths, some quite long, so I had to measure them all to get new ones. In spite of replacing everything and using the new style gasket, I still had a small drip around one of the bolt heads after pressurizing the system. I got an aluminum washer with an integrated o-ring in it, and that cured the issue. I bought the new pump from SNG Barratt. It came with the old style paper gasket which I threw out.

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Hello Alex,
My very recent experience is with an e type V12 water pump. I had mine refurbed by a local engineer. I also questioned the “stiffness” of the pulley when the pump was returned. He explained that there was a "mechanical " seal of two faces which caused the drag. Once installed the pump is fine with no leaks. I used a new paper gasket as supplied with a careful smear of Loctite 515 on both faces of the gasket. All threads of the bolts & holes were cleaned up with a tap & die as required. All threads were all coated with anti-seize before installation. So far so good.


So, my ocd kicked in and as I was about to install that rebuilt pump I thought I’d rather wait a few days and have mine rebuilt. There is no logical advantage, just the irrational satisfaction of knowing that the car will be running its “own” pump.

In the meantime, I was finally able to remove the fossilised plug, which I indeed replaced with John’s contraption, been doing all the flushing and back-flushing, cleaning etc etc. It all started with the tiniest of hairline cracks in the right crossover-to-coolant rail hose. I believe the term to describe what’s been happening since is: mission creep.

Anyway, the pump bolts. The holes they came out of are full of debris, rust flakes, mud, you name it. I’m planning of flushing all that out with a combination of air and water and then use a brush to clean the holes. Didn’t think of going as far as tap & die, but if you say so.

I’m supposed to receive a “high quality” gasket: EBC9629 - WATER PUMP GASKET HIGH QUALITY – M&C Wilkinson Ltd

Would that, being “high quality” (foam coated steel), NOT require any additional goo (Loctite, Hylomar, etc), or are these essential either way you think?

No, it’s shipwright’s disease.

Your brush looks good. For others, note that you can find suitable wire brushes for cleaning a wide assortment of hole sizes at any decent gun shop.

Interesting. Jaguar, under Ford’s umbrella, introduced the gortex sandwich gaskets, which are black foam coated metal, aluminum I think. They work great, but it appears most rebuilders have gone back to paper.

The Ford gaskets are supposed to be installed dry.

Been ‘looking ahead’ at water pumps, and it seems Jaguar no longer sells OEM. Most Jag retailers seem to sell a NEW aftermarket at about $150. I don’t really see rebuilds.

Also wondering, with only 60,000 miles and these water pumps are pretty long lasting, should i just leave it be? Can it be replaced without removing radiator?

The radiator is the least of your worries. The water pump is basically buried behind a lot of the belt driven accessories, some of which use common mounting studs or bolts with the pump. A lot of them need to come off. Since you have the front suspension off and removed the power steering pump, you are part of the way there and have better access. Removing the radiator gives you a lot better access and lessens the risk of damage to the core.

Look closely at the other components of the cooling system. If you have or had a lot of rust or corrosion in the cross pipe, header tank, radiator bleed pipe, or the thermostat housing covers, the waterpump won’t look any better. Plus, seals go bad from just sitting, just like engine oil seals.

My 87 has 50k miles, and had received decent maintenance over the years. The water pump I removed looked reasonably good, but the mounting bolts and studs were awful with lots of rust and thread damage. I’m glad I didn’t wait, even though it was a PITA to do. I was doubly glad I did when I found the header tank had rusted thru, even though it looked perfect on the outside before it sprung a leak.

Terry’s sell rebuilds, but they are more expensive than one of the new ones they sell. How good a rebuild it is unknown.

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Luckily the other components were in pretty good shape with very minor corrosion. When I bought the car, coolant was nice and green. But you’re right, probably worth replacing soon. But I’m going to wait until I have radiator out later this year. I don’t mind having to remove a few odds and ends.

I would trust a rebuilt 88 OEM part than a new aftermarket part, may see who can actually rebuild mine directly.

Gah, always a tough call. I’d leave it, personally. In the grand scheme of things I don’t think we see that many w/p failures. As you say, they’re long lasting.

On the Series III sedans, yes. Pretty sure on the XJS as well. Been too long for me to remember. In either case, it ain’t a 20 minute thing :slight_smile:

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Cheers
DD

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imo… if any part like that gets removed… in goes a new fresh one… the proverbial story about the used part going bad the next day… labor labor

Kinda surprised anyone is making new pumps. That said, what would one suppose is the difference? Presumably anyone rebuilding a pump is installing a new bearing, a new seal, and a new gasket between the halves of the housing. Maybe a new impeller. If they’re offering a new pump, presumably that means a new aluminum casting and a new cast iron impeller? Otherwise, the same new bearing, seal, and gasket.

So it would seem the only difference between new and rebuilt is the aluminum casting and possibly the impeller. Do you suspect an aftermarket company can somehow make a crummy aluminum casting?

Perhaps the impeller is the biggest concern. The vanes on the Jaguar impeller are famously strongly backward-leaning, whereas the vanes on similar Chevy impellers are either slightly backward-leaning or even slightly forward-leaning. The lean affects the performance of the pump. I put a Chevy impeller in mine, worked great. Between Chevy and Jaguar, I’d conclude Chevy knows more about keeping an engine cool. None of this means anything about a new aftermarket pump, of course – the aftermarket company might be faithfully reproducing the Jaguar cast iron strongly backward-leaning vane impeller.

I wouldn’t trust a rebuilt unit anymore than a new one. All they reuse are the front and rear castings and pulley. The bearing cartridge, seal, and usually the impellor are replaced. The bearing cartridge has the bearings in a unit. Where an aftermarket rebuilder gets those parts is a crap shoot. New bearing cartridges and seals don’t seem to be available from Jaguar anymore. I’d trust a new unit from a quality source before a rebuild using unknown parts.

Perhaps not, but the seal is an industrial standard, you can get one from Grainger. And the bearing cartridge is very similar to those used on zillions of cars, the only difference is the length and diameter of the shaft on each end. I have long surmised that there is a bearing cartridge out there that fits perfectly, from some particular Chevy model or whatnot, I just don’t know how to cross reference bearing cartridges.

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Here’s the seal at Grainger:

This is basically the OEM type seal, except the one sold at Grainger is probably better quality.

Or you can improve over OEM and get this one:

This one has a carbon running face and a Viton diaphragm, as opposed to the plastic running face and Buna diaphragm of the OEM part.

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