Thread: An important question about Defender cooling sytems ... (Yes, it's general chat)

Mud....left over casting sand??

Vlad, there's this stuff called coolant that contains inhibitors to prevent corrosion, but it does have a finite life and the 'conventional' style ones will suffer silicate dropout when their useful life is over...

Originally Posted by VladTepes

Should the cooling system, when drained, produce volumes of what looks very much like mud ?
Should the hoses be crispy?
Should a steel pipe be rusted at the ends?


Asking for a friend.

@jboot51

No
No
No

Originally Posted by DiscoMick

No
No
No

I have never drained an old neglected cooling system yet that didn't produce a significant amount of sludge. Coolant treatment was unheard of in the fifties and sixties and all sorts of folk remedies were poured into radiators to stop corrosion or plug leaks. Soluble oil was popular. Ground pepper, egg whites for leaks. Washing soda was used to clean dirty systems.

sludge....where does it come from

I was astonished when I pulled down the fuel cooler on my td5 to find a reddish/brownish sludge or sediment in a large enough quantity to be concerned as to how it got there in the cooling system. I cleaned it all out of course but couldn't help wondering if there was more throughout the system.

Subsequent new radiator/cylinder head and flushing probably removed all traces but I always wondered where it came from in a system that was never opened.

is why the greater being devised back flushing

Originally Posted by ramblingboy42

sludge....where does it come from

I was astonished when I pulled down the fuel cooler on my td5 to find a reddish/brownish sludge or sediment in a large enough quantity to be concerned as to how it got there in the cooling system. I cleaned it all out of course but couldn't help wondering if there was more throughout the system.

Subsequent new radiator/cylinder head and flushing probably removed all traces but I always wondered where it came from in a system that was never opened.

Probably mostly corrosion products from the metal parts of the system, plus breakdown products from the rubber parts, plus breakdown products of the coolant, and possibly some remaining casting sand.

Like I said "Asking for a friend" because I'd never neglect a cooling system so badly that I didn't even realise how bad it was.

But just in solidarity with my friend, I've replaced all the relevant parts and coolant etc.

You know, just in case.