Got my STR running a nice temp after my last thread, but upon inspecting the coolant level a few days ago, about a week after bleeding, I noticed a small drip from the coolant bleed valve atop the plastic tank. Took the screw out, cleaned it, reseated it, careful not to over-tighten. Went to check the coolant again today, and still leaking. So I removed it, wrapped the chamfered bit in PTFE, Reseated and tightened - careful not to over-tighten it. Except I did, and it sheared off. I suspect it was already weakened, and the PTFE (Cowboy, I know, but I had no other ideas...) allowed all the force to act on the base of the screw and tear itself in two. We're not talking a lot of torque here. Now aware that the 'chamfered bit' is actually a sealing ring, but I doubt it would have sealed anything as it's rock hard and misformed.

Managed to get the remaining thread out by lightly tapping a screwdriver into it and gently screwing out.

Not the end of the world, right? Car off the road for a few days whilst Jag send me a £2 replacement with a fresh seal, screw it in and off we go... Time for a cup of tea and a scroll through the parts catalogue.

Searching the parts catalogue reveals I am about to be stung for an entire new coolant tank as the bleed screw doesn't appear to be available separately!! Please tell me I'm reading something wrong and this is not the case!? Does anyone have a part number for just a screw?

 

Bite the bullet and replace the entire coolant expansion tank. They get brittle and tend to suffer from various leaks with age and repeated heat cycles. Some of the worst plastic you'll ever encounter as many long-time owners have noted over the years. I replaced our 2005 S-Type's coolant expansion tank in late 2009. Won't be surprised if I have to replace it again if we keep the car long enough....

 

I have a spare bleed screw if it is any good to you let me know.
Rich.

 

It's false economy to just replace the bleed screw. As you noted the plastic has decayed from time and heat.

As was posted above the tank is also decayed and I would just replace the whole thing. I think I paid about $130 from Jaguar. Tank comes with a new bleeder and a new temperature sender too.

If you have not serviced your thermostat and coolant I would take this opportunity to do both.

Do you know to use the vendor that gives forum members 15% off plus free shipping on orders over $25? Greenville Jaguar and Jeff Durham have treated me well.
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My tank is 3 years old and has begun to leak at the same exact spot again. It's intermittent too which I find very odd. It's that small nipple at the top and it's shopwing cursted orange coolant remnants just like the last time.

I'm seriously thinking about having a metal one made if it's financially feasible.

Their coolant plastic parts SUCK. This is just absurd.

 

The problem is the quick disconnect connection to the molded plastic hose that falls apart in your hands if you aren't careful - the one underneath the tank, otherwise it would be pretty straight forward.

Every jag I have owned the recovery tank has failed. My x-type, 2 s-types, my Xjr was the most spectacular. - blew the nipple off under pressure at 4k rpm.

When I lost the x-types, which has two nipples not one, I actually used 1/4 barbed brass air line couplers, and heated the tank plastic to get them to go in. Then sealed with jb weld. 3 days later when I got my new tank, there was no sign of a leak.

Take care,

George

 

Does anyone have a discarded tank they'd be willing to donate toward a project to make one out of aluminum?

I think I'd get it powdercoated semigloss black instead of trying to bling up the engine compartment. What's the point of showing off a header tank that's probably not going to end up being shaped quite as nicely as the original?

I'd like to see just how feasible this is going to be?

I still can't believe they never addressed this issue, I have Italian cars that are 30 years old and they came with a milky translucent plastic header tank and I've replaced them once in 30 years not once every 3 years!

This will require a decent fabricator as well. I'm just pissed!

 

Never addressed - bearing in mind they ceased production 2 years after your car - in what sense?

They needed to get it right from day 1 but didn't and had stopped production before even knowing it was wrong I think.

 

Yeah probably though I think some bean counters and cheapo engineers had to know they were using crap plastic. Model airplanes got a better grade than this s**t.

I wish I thought I could repair this but I do not have any confidence in gluing plastic for the long term. One of my older Maseratis came with plastic end tanks crimped onto an aluminum core and it's still OK but it did have a plastic screw in barbed nipple for the header tank at the top. That failed early on so I replaced the nipple with a brass one and after almost 40 years it's still holding.

Hard to see how this thing is reliably repaired but I'm open to suggestions.

 

Wish I still had my old one. I did experiment a bit with trying to use a brass nipple after my plastic ones broke, but I never got it to seal right.

 

The coolant expansion tank in my 1999 Dodge Ram pickup is made of a much heavier and thicker plastic that seems impervious to heat cycles. Even though the plastic is much thicker, the tank's hose nozzles have some flex in them which I believe is critical because the nozzles remain far more capable of mitigating the constant road vibration, the inward pressure from the hose clamps, and the heat underneath the hood. I wish I could adapt a Ram tank to both of our Jaguars, but it is tall and narrow as opposed to Jaguar's short and squat tanks. Aluminum tanks are not necessary when nothing more than a much better grade of plastic would solve this perpetual problem permanently....

 

Thanks for the replies - and the kind offer of a screw(!)

I bit the bullet, borrowed my housemates mx5, much to his amusement, and went to fetch a whole tank assembly from the local Jag dealer. Had a bit of banter with the guy on the desk and got a 10% discount. Haven't had chance to fit the tank yet - on the to-do list - but nicked the bleed screw and popped it in the old tank for now. No more leak.

I did mention the issue to a friend who is a fitter, and after a few seconds with a set of digital micrometers he identified the screw as an M14 coarse thread, a 50mm bolt for which would set you back about 3 pence, and 10 minutes with a hacksaw and a file would give you an almost invincible replacement. He also mentioned a lot of GM vehicles use M14 plastic drain plugs for sumps, so if anyone has the same issue, this may be a cheap (albeit temporary from what I read above) and easy fix.


Next to sort these +20% LTFT's out