Thread: Help! Another expansion tank cracked......

I wonder if your car is getting very hot and therefore having high pressure in the tank.

Did you change the cap when changing tanks?

Do you often switch off straight after heavy going so that heat soak increases the water temp?

Just that my D2 TD5 has the original tank at 186KK with no hint so far of cracking etc.
Regards Philip A

Originally Posted by rusty05

I can see this is a bit old, but am interested in this, as it is happening to me as well
I have had 2 non genuine crack and a genuine crack in the last 18 months, I ve also had the head gasket replaced 10 months ago, but that didnt make any difference.

I am having trobles beliving its a HG, but also troubles thinking it is bad genuine and non genuine tanks
They only last 3-9 months.
They have cracks appear mostly on th top, and start to weep from them, they never seem to leak at the join.
Do the genuine ones have LR stamped on them, as the one I got didnt, it looks just like one of the cheap ones I have used in the past.

The aftermarket ones are crap, you said you think you replaced one with Genuine, but your are unsure, if you had a coronary when you purchased the genuine one then probably was a genuine tank, if it was cheap then probably just another aftermarket one. There are a lot of cheap aftermarket ones around, the reason they are being sold is customer demand for cheap products, not worth the hassel in my experience. Plenty of sellers eager to take your money on them though.

Originally Posted by PhilipA

I wonder if your car is getting very hot and therefore having high pressure in the tank.

Did you change the cap when changing tanks?

Do you often switch off straight after heavy going so that heat soak increases the water temp?

Just that my D2 TD5 has the original tank at 186KK with no hint so far of cracking etc.
Regards Philip A

No I didn't change the caps.
but will go get a genuine one .

The cruise into my street is easy so there shouldn't be any excess heat/pressure

Originally Posted by Roverlord off road spares

The aftermarket ones are crap, you said you think you replaced one with Genuine, but your are unsure, if you had a coronary when you purchased the genuine one then probably was a genuine tank, if it was cheap then probably just another aftermarket one. There are a lot of cheap aftermarket ones around, the reason they are being sold is customer demand for cheap products, not worth the hassel in my experience. Plenty of sellers eager to take your money on them though.

Hi RL

i did have a coronary at the price, but did expect it to have a LR stamp on it.
i bought the genuine after 2 cheapies cracked.
but the genuine looked just like a cheapy

For a DIY check on the cap you could extend the overflow tube with a clear plastic hose into a hole in the cap of a 600ml drink bottle, you would need to drill a small vent hole or leave the cap loose with the hose going to the bottom of the drink bottle then fill the coolant tank higher than the high mark to guarantee the cap will release some coolant, when hot you should have the displaced coolant trapped which will be sucked back into the tank when cool, the hose in the drink bottle needs to be submersed for this to happen.This will only check the valve in the cap and not the pressure the cap will hold.
The OP said his tanks cracked on the top i will check the flex on my good tank with a straight edge from guard to guard over the tank and measure with verniers the movement between hot and cold of the top, when it stops raining that is.

Originally Posted by rusty05

No I didn't change the caps.
but will go get a genuine one .

The cruise into my street is easy so there shouldn't be any excess heat/pressure

I have changed the cap and can tell its diiferent to the one thats been on it for the last 8 years iv had it.
Genuine cap, so thought the one it was non genuine then, problem looking like sorted, but nope.
It still just showed signs of its first crack appearing and a weap of coolant.

Did anyone every have success in finding a aluminium version, the ashcroft is only D1, maybe thinking about using that and doing what ever is needed to the mounts, if the plumbing side is similiar.

Originally Posted by rusty05

I have changed the cap and can tell its diiferent to the one thats been on it for the last 8 years iv had it.
Genuine cap, so thought the one it was non genuine then, problem looking like sorted, but nope.
It still just showed signs of its first crack appearing and a weap of coolant.

Did anyone every have success in finding a aluminium version, the ashcroft is only D1, maybe thinking about using that and doing what ever is needed to the mounts, if the plumbing side is similiar.

Hard to see a metal one being stronger than a genuine plastic one, although I guess the metal ones could expand. The genuine one should definitely NOT crack before the cap releases pressure. There is a fault somewhere, IMO. I would first suspect the cap, as it is intentionally the weakest point in any pressurised cooling system.

Dont look at me... I have no clue...

But as Mario has pointed out plenty of non gen are really crap.

On a side note though.
While a Discovery 1 and Discovery 2 expansion CAP may look the same and err umm sort of screw on. they are the same thread but a different pitch and arent inter-changeable.
BUT I think from memory, might be Britpart list both as the same part number..

Regards
Daz