I have a leak or crack somewhere in the tank or hose connected to it, I can visibly see the drips underneath when it gets hot.

Can someone post how to remove for inspection?

I already added the stop leak which didn't make any difference.

If I find the crack can I use JB Water Weld to fix the crack, or would something else work better?

 

I've done this a few times.

1. Suck out all the coolant from the tank. Disconnect the coolant sensor pigtail.

2. Remove the hoses from the top of the tank.Pinch them off if they leak.

3. Remove the bolt. Its easier to get to the bottom hose.

4. Remove the bottom hose. Pinch it off or use a wine bottle cork to prevent spillage.

5. Its out!

I don't know if JB Weld will make a permanent fix. I often wonder if several coats of Flex Seal (As Seen on TV) would fix it.

 

It could also be a leaking cap...around 20 bucks to replace.

If it is the tank that is cracked also replace it. Don't bet your engine on some JB-Weld. It will fail again under the stress of temperature and pressure.

I hope the Stop Leak has not made the problem worse. Here is a quote from a post on another XK8 forum:
"Have messed up big time, added Bars leak with carbon fibers
to cooling system. Now all these fibers are accumulating in
pressure cap and does not allow pressure to build up. Have
pressure flushed system 3 times and still have fibers
floating around. Considering an in line filter of some kind
to catch fibers before expansion tank. Think original
problem was expansion tank neck and cap not holding
pressure, now replaced. Have bench tested cap and will not
hold pressure with just a trace amount of fiber in there.
They accumulate like a cotton ball fiber."

 

After two attempts with JB Weld I can attest to the fact that it will not be a permanent repair. Mine cracked away from the seam and I roughed up the plastic to the extent that it had both a rough surface and 'feathers' for the epoxy to attach to. Lasted a few months.

 

Agreed. Sooner or later they all fail. The only sure bet is a new tank....

 

+1 on the new tank. Verify it is not a hose or the sensor on the bottom that is leaking first.

A new tank will come with a new sensor and a new cap. Cheap insurance for your engine.

 

If it keeps leaking out the bottom, not from the cap, and it shows low coolant, is that low enough to remove hoses and take off to inspect, or do I have to suck out more of the coolant?

 

NO - the outlet is at the bottom so you either need to suck the tank almost empty or lose the coolant in the tank when you disconnect the hose.

Graham

 

And if I need to do a temporary fix on the crack until I get a new one, what should I use?

 

I had good luck on another application with WaterWeld which is a JB Weld product for water-use solutions. You will need to drain the tank so the epoxy can dry correctly.

Despite the fact it might hold long-term, I would not use this as a permanent fix. You will just be doing it again on another spot eventually...most likely at the worst possible moment. Once the plastic in those tanks start going, they never get better.

 

Are there any special tools required to take off the tank or the hoses?

 

No special tools needed.

 

Maybe a TROX bit as my reservoir mounting bolt is that but most of us don't consider that a special tool . . . and a pair of pliers for the bottom clamp. You also need to know how to release the small hose clamps. Easy to do if you know how.

 

I am not mechanical at all, with very limited tools, and no TROX bits, do you happen to know the size I will need?

How do I release the clamps?

 

You will need a T27 for the expansion tank. Follow the instructions from mromanik at the top. I also added a towel under the tank to catch coolant, and I replaced the clamps at the same time. Just squeeze the outside "humps" with the pliers towards each other.

Once you are done, start the car and let it warm up to esnure no further leaks. I had to adjust the screw type clamps afterwards, since it was still leaking coolant.

If I can do it, ANYONE can do it..

 

I was going to use JB Water Weld to try to fix the cracks, is there something else that would work better?

 

A new tank.

You do understand that a sudden evacuation of the cooling system may overheat the engine to the extent that it will need to be replaced?

 

A new tank.

I fixed a leak on the radiator tanks with this stuff. It will easily hold on the expansion tank if applied correctly.

But as mentioned before, use it only until you replace the tank. Not that it won't be permanent, but that the tank will simply start to leak somewhere else.

 

This is just to fix it until I get a new tank.

 

Meaning making sure it is completely dried and sand papering it down so the JB Water Weld will stick correctly, or something else?