This is my 3rd post on the subject, and I want to thank everyone who has helped to thus far. I have a 2013 XJL 5.0. I has a coolant leak and was told I needed to replace the water pump. I wanted to do it myself. After reassembly, it couldn't hold pressure, and water quickly leaked from the back of the water pump. Initial post is here:
https://www.jaguarforums.com/forum/xj-x351-53/f-u-water-pump-removal-flush-shows-leak-plan-attack-282399/

I took everyone's advice and tried again. I believe i made 2 errors. First, i did not set the aluminum pipe (replacing the plastic part) behind the water pump correctly, as I did not turn it to the right to secure it. Furthermore, I did not place the o-rings correctly as instructed. I also used Vaseline to help replace the hoses- this made a huge difference in moving them about. I also got a torque wrench. When I took the gaskets out they were flattened but complete.

This time i made sure the o-rings were correct and the pipe correctly placed. I threaded the gaskets through the bolts before putting it in place- actually I connected the hose first as well as otherwise it is a pain to get that hose in place. I made sure all the bolts aligned and hand tightened and it felt correctly seated. I then used the torque wrench to 12.0 N/m. I put back the belt and hoses. I plugged the radiator with the cap.

This time I pressure tested the system with air, and was able to build pressure. however, it could not maintain pressure. I set pressure to 15 psi... but in 30 min it was 14 and 1 hr later it was 12 or 13.

This seems like a pretty slow leak. My question is- what is the likely culprit? How can I find where the leak is? is it possible or likely that the gaskets are leaking from wear of the first install?

Thanks!

 

I filled the system and it didn't leak. Then I pressurized the system and saw this leak on a hose I didn't even touch!

The hose clamp is not all the way on!

How do I remove this clamp type? Without breaking it?

 

Ok, I figured out this was a Norma Cobra clamp. I was able to remove it, re-seat the hose, then reattach the main radiator hose. I put 16psi of pressure of air and it held 30 min.

I think I'm good to go to put together the air intake and air filters, then run the engine.

 

Thanks for that as I did not know those factory crimp clamps could be taken off and on!
Does it take a special set of pliers?
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No- but there is a special technique. I found it on another forum. Basically, there are "inner" "ears" and outer ones. If you clamp down on the outer ears, the thing will pop open. It took me several tries with different sets of pliers to get a proper angle. Eventually it did pop open. There is a special tool for it that makes it easier, but I didn't have the time to order it. To close, you repeat the exercise, but press together only the inner ears. It does not take a lot of pressure, and I did this with... surgical clamps.

 

OK thanks as I kind of see what you mean? I have searched and it seems those pliers are only sold in Au.?
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There are these types of hose clamp pliers/crimpers and ones like them:
More Information for S.U.R.&R. CP360 (rockauto.com)

Hoses/Lines & Clamps > Tool > Hose Clamp Pliers | RockAuto

 

Donīt want to know why you have surgical clamps in your garage or what happens in your basement.

 

Hey man, Jaguars and their repairs are expensive. Sometimes you just need to sell a kidney or two.