Topic

Sounds familiar! I did the same before i found the crack.

David Aiketgate wrote: wrote:

Sounds familiar! I did the same before i found the crack.

Ok, I tracked the leak down. It appears to seep through a weakened joint in the plastic of the expansion tank.





Inside view -



I've tried a hasty repair to stem the seeping. I warmed up the tank, but didn't put the cap on. So there's been no pressure on it as yet.







I'll try it under a bit of pressure later and see if it holds up under the strain. Do you think it might?

It will probably hold, but I would get a new tank.

If it's cracked once, it must mean that the plastic is brittle.

David Aiketgate wrote: wrote:

It will probably hold, but I would get a new tank.

It didn't hold so I swapped the tank for another one and then the cap gave out. New cap and all is well.. for now.

One thing that I can add to this thread for finding pesky leaks is the use of coolant dye and a UV flash light.

Here in Canada I can buy a kit at Canadian Tire, which is sort of like Halfords but with a better reputation, which includes a couple packs of coolant dye, a UV flash light and yellow-tinted safety glasses. The yellow-tinted safety glasses are suppose to make the dyed leaking coolant more visible but they are not needed.

I had a leak in the hoses on my F in the same general spot as Leigh, the heater in/out assembly. It was small and the heat from the engine would evaporate the leaking coolant. By adding the dye to the coolant I could see the dye stain in the hose using the UV light.

Just lately my car's been rupturing like a haemophiliac. Here's the latest source of blood loss that I found when taking some random underbody shots whilst having my new exhaust fitted. I'm convinced that I'm chasing the pressure around the system and fixing it as I go.

I'll nip up to B&Q tomorrow and clamp that area with some jubilee clips. Then see where the leak goes to next. Oh the joys of MG ownership. It can be so underwhelming at times.



Here's how I fixed it. I just pushed the hose down and clamped it with a jubilee clip.

might be time for some st/st pipes Leigh

That's the thing with pressurised systems, water will always find the weakest part. Fix that one it will find the next... Hope you get it all sorted soon Leigh, I know how frustrating it can be.

Mine has a small water loss, started with the expansion cap which i swapped, was fine for a week or so then started losing water again this time also when stationary. Turned out to be the expansion bottle so new one ordered and fitted and all was ok for a couple of weeks. Now started to lose water again, about 1mm per 100 miles, so not a major loss, but I want this car ready for our wedding, which gives me a month or so to sort it out...

UV dye and black light on order, just waiting for the dye to be shipped...

Cheers Mal. That's something I'll bear in mind.

I changed the hose from hell today. Reaching to unscrew and remove it is a nightmare.



All good again, so far and I enjoyed a bit of noise from my new exhaust which was long overdue.

Good luck for your big day.

What's this leaking thing inside the red circle please

That's the thermostat housing, Leigh.

Dunno but I've taken one off and given it away now doh!