I posted yesterday about replacing my water pump on my 2013 XJL 5.0. This is my first big project.

last night I removed the old pump and olaced the new one. I also replaced the plastic connector in the back with an aluminum one, and also added a new rubber seal. I secured the bolts on the water pump snugly, but tried not to over-tighten.

This morning I put the serpentine belt and all the hoses. I also put back the air filters and manifold.

Then I tried to pressure test the cooling system... i couldnt get pressure. I thouggt i might as well flush the system to see where the problem was. I put about 1.5 gallons of distilled water, and there was a steady drip, far worse than the original (very slow) leak. I was thinking the radiator drain ****, but it seemed to be coming from behind the water pump (see picks).

What's The likely issue? What could i have done differently to not waste so much time replacing everything to test if the pump is secure?

Thanks again!

 

Most likely the water transfer tube that you replaced that runs from the back of the WP to the oil cooler brick. Many posts about this.
Did you lube the O-rings with coolant? We have had suggestions to NOT use the WP bolts to seat the tube but I have not changed mine as it was done under warranty about 5+ years ago.

I think it needs to come back apart for further inspection.
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Snugly?
To me "snugly" sounds about like finger tight.
I don't know if "snugly" qualifies as the required 12 Newton meters (106 inch/lbs).The gaskets work great, but not if the pump screws are not sufficiently tightened.

 

Thanks all.

I did not "lube" the o-ring with coolant- I will do that next time. Of note, there was an o-ring between the oil cooler brick and the plastic adapter that I replaced with aluminum. it looked a bit worn, so I took an o-ring from a new adapter that came with the water pump (intended to be used between the adapter and water pump, and placed it between the oil brick and the adapter. Maybe I should not have done this.

re: "snugly" I tightended the bolts with a ratchet and M30 bit so that there was significant force required to go further, but I could ratchet further. I worried about smashing the metal seal that has a bit of a lip to it- I though if I press too tighly it would crush that seal.

 

When I did my water pump about 8 weeks ago. I used 2 new genuine Jaguar O rings not the ones that came with the aluminum adapter. I fitted one o ring to the nipple of the oil cooler and slid the adapter on to the oil cooler and rotated the adapter so it is locked longitudinally in the cylinder block, then fitted the second o ring on to end of the adapter which fits into the back of the water pump. I then carefully slid the water pump on to the adapter eyeballing the bolt holes. Inserted the four bolts while holding the water pump, tightening them with spare fingers. I checked that the aluminum adapter was still located properly at the back of the water pump and at the oil cooler. Then I used my fancy new miniature torque wrench to tighten the bolts to the specification 12NM. I used Vaseline to lubricate the O rings. The 2 water pump gaskets were installed dry. I have completed 10k kms since without adding coolant.

I notice in your picture from yesterdays thread that old o ring is still on the oil cooler nipple I hope I am correct in thinking you removed it before installing your new aluminum adapter.

 

Attached is Jaguars way of fitting the O rings

 

I did remove that old o-ring and replaced it with the same type of o-ring that goes on the other end of the aluminum adapter.

Is it OK to use Vaseline on the O-rings? Also, how did you keep the gaskets on while installing without them falling off? Man, this was such a pain.

Thanks!

 

Vaseline is not a problem---its even good for human skin. Regarding the gaskets I pushed the bolts into the pump casing so that just a couple of threads are exposed on the backside then hook the gasket over the second thread top and bottom. when you offer up the water pump to the aluminum adapter you will feel some resistance as the the water pump engages with aluminum adapter then you can start turning the studs with your spare fingers. After you have engaged a few threads take a look around, use mirror if you have to, ensure the gaskets are in place and aluminum adapter straight ---you are then good to go and tighten the bolts.
It took me 3 attempts before I was happy and tightened the bolts. Also note that the O rings must be pushed to the end of the oil cooler nipple The o rings have to seal inside and outside of the nipples as shown above
I hope it works for you

 

The raised part of the pump gaskets is supposed to be crushed - that's the way it seals when the 4 bolts are properly torqued.
If you didn't tighten them enough to flatten the gaskets, they won't seal.
On the sunny side, if you didn't fully crush the washers they may be able to be re-used if you're going to remove the pump & check the oil cooler adapter o-rings.
But make sure you torque them to 106 inch/pounds when you install the pump.

The o-rings front & back of the adapter are the same, so the two new ones you used should be good. Unlike the metal coolant pump gaskets, the o-rings are re-usable.
You can use spit on the o-rings. I've just wiped some spit around the o-rings when needed & it works fine too.

With the pumps I've used, the gaskets have come with them already attached & ready to assemble screws & all. It's more of a pain to me to get the gaskets to come off the threads of the bolts - not that they need to come off though.