After being in lockdown for a few months I was exited for the drag racing day yesterday, but nope, defered maintenance got to me first. For the last few months I had a slow cooling disappearance somewhere, I was suspecting a water pump but figured I would wait. Well it decided to start leaking really bad on the day of the race, what are the odds but it is what it is , good thing I caught it in my driveway and not ran out of coolant at the drag strip, could of been bad..
Fingers crossed that it's just the water pump and not the valley hose...

 

Sometimes you get lucky that way. Ain't no better place to have breakdown than in your garage or the driveway.

 

Yes exactly so at first I was thinking how unlucky to have it happen on race day,, but it could of been a disaster loosing coolant at the track so I consider myself lucky

 

Having been on the track a LOT I can tell you that there's nothing more frustrating from the perspective of the track owner and the people waiting to race than a giant patch of antifreeze. It's the worst to get up and it takes forever. While I never want a breakdown, I'll say that it happened in the best possible place. You'll be back up in no time.

 

Yup, mine looked just about the same. Get yourself a decent replacement with a machined mating surface, and metal gasket. I did not have success with the paper + RTV gasket type replacements.

 

Thanks for the tips! Hope it's not the valley pipe

 

So bad news from the mechanic..
pump replaced but when system pressurized to 20psi, radiation leaking on the side , several hoses and the valley hose under supercharger also leaking. When pressure only at around 15psi no leakage.
Never noticed the radiator or any of the hoses leaking before. Is this do to excessive pressure while testing? I'm confused, here . Really not looking forward to spending all the bucks for new radiator and valley hose replacement

 

You might not have noticed because it didn't hit the ground but fell into the pan under the car and then evaporated. That's what happened to mine as I was losing coolant every night.

 

The only leak I ever saw was from the pump. I wonder if 20pso they used was just too much for the system
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This is exactly why I always carry a Geiger counter. ..... and SOME people laugh at me for it.

 

I guess,, you may have to research for the safe working PSI of the RAD and hoses. I've tested my vintage Mustang to 15- 18 PSI with not detriment. Perhaps, the Rad is/was marginal? Perhaps the hose clamps needed tightening?

 

If the prognosis is that you need to replace a bunch of pipes and hoses coz they leak under high pressure but not otherwise then maybe a better and cheaper route would be to change to Evans waterless coolant? Almost zero pressure and the cooling system components last a helluva lot longer.
This is not a plug mind you, I have never used it, but I have read lots of good things about it.

 

True. I had goopy specs on a tranny pan bolt, around the cats, bell housing, those areas. From an intercooler hose.

Leaking TB, EGR, and valley hoses would tend to flow down the valley.

For a GM cooling system (4.0 jeep):

Not sure what the Jag spec is but a leak is a leak, unfortunately. Good luck man!

 

The pressure cap rating is just over 17psi so the system should never see 20psi but that is more than 15psi.

 

Evans is great but it doesn’t fix leaks it just helps keep them from happening in the first place. Twenty PSI is too much, fifteen should have been enough. The good news is all of this was likely to happen at some point and now won’t happen at an inopportune time such as on the track. Also a good time to replace all of the hoses with a better product and perhaps do some porting on blower, throttle body, intake, manifold and blower outlet.

 

Well if the Mechanic messed things up by going to 20psi, that's an issue and an unnecessary expense, not sure I want to continue working with them if they screwed up like that..should of just worked on the car myself for my piece of mind, now stressing over on what else they will screw up on

 

I knew I was correct...

From the workshop guide:

Do not exceed 1.0 bar (15 psi) whilst pressurizing the cooling system.Slowly pressurize the cooling system until the pressure gauge reads 1.0 bar (15 psi).

Make sure the cooling system holds pressure for 5 minutes, note that a small pressure decay of approximately 0.15 bar (1 psi) over the first minute is normal.

 

Sun of a gun! Mad So he caused more damage than he fixed...
Jahummer is in our service manual?

 

The 4.2L workshop manual is a little confusing actually.

Under the section for 'cooling system pressure test' is says:

• Pressurize the cooling system to the coolant expansion tank pressure cap lower limit.

Under the section for 'Radiator Leak Test - Removed from the Vehicle' it says:

• Leak test the radiator in clean water with 138 kPa (20 psi) air pressure.

Under the section for 'cooling system flushing' it says:

• Connect a hose pipe to the radiator upper coolant hose connection
  using a suitable connector.
  
  CAUTION: Radiator internal pressure must not exceed 100 kPa
  (14.5 psi). Failure to follow this instruction may cause damage to
  the radiator.

 

That's a little misleading in order to test the radiator pressurise to 20psi however in order to not cause potential damage please do not exceed 14.5psi as damage might occur ????