In the 2 Mini's that I have, the coolant level sits about 1 inch below the very top of the radiator neck.

If I fill it to the top, and run the motor, it will 'overflow' (with cap on) till it reaches this level.

Is that right?

On another note, if I fit an overflow bottle, with coolant return to the radiator, do I need a different radiator cap? And does the position height of the overflow bottle have any effect on it's abillity to return coolant to the rad?

iv had the same problem with my radiator level and it overflowing,iv been told to keep it at about an inch below full,seems to work out fine.

hrmm, are you sure you have the right cap Anton? there are 2 types, one has a longer neck.

I keep mine just level with the top of the radiator gills and it doesn't overflow...

I am pretty sure that the overflow system is a pressurised system and uses a different cap, but I could be wrong

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Lillee - 1969 Morris Mini K

it is normal anton every mini i have ever owed dose it
makka

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thought so thanx makka

no worries mate gee i'm being helpful today .... i will have to spam some threads to make me feel better
makka

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Anonymous moderation means the agro that is built up towards the mods isn't aimed at an individual (fewer "Makk" attacks). Less stress for mods means less moderator "retirements".

I fitted an overflow to mine Anton, coz I wanted to avoid having to top the radiator up all the time coz it would spit some out every time you stop basically, gradually needing constant replacing just because the engine heats up, water expands, pushes a bit out and loses some to evaporation from the hot radiator and engine.
The overflow works great, yes you do need a different cap and if the throat of your radiator isnt the right one I dont think you can do it. I got my radiator professionally cleaned and they replaced the top neck and cap housing coz they didnt have a cap that would fit properly I mounted the overflow tank just behind the grill next to the radiator and seems to be working perfectly

Repco sells them for $19 or $25, white plastic, match the replacement washer tank/motor tank also.

Edit: my overflow tank

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com

yea I got a overflow tank from a Hyundai Excel...small and nicely shaped. I was thinking about the exact same spot you mounted yours.

My rad has been redone by Natrad, and it looks like they have replaced the neck....it's been soldered on and is slightly crooked

What is the visible difference between the necks then?

Im not sure, Id guess the overflow exit point must be positioned so that fluid can get back in when required. Between two flanges/seals in the special caps?
One seal would stop water getting out the top radiator cap, but the lower seal would aloow water into overflow tank and back in?
I didnt have a really close look it it, was going to, but then thought its working, who cares how

edit: Closeup of the neck and cap

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com

thanx for that! cap is definitely different!!

sorry but it has to be said, "nice hand modelling there Jill!"

Cheers

Aaron

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The radiator cap on my Moke is just flat inside without any springs or such, only a flat piece of rubber inside it. The cap on the overflow tank is the normal looking type cap...

`tis true.
Water is basically incompressible, and also expands when it gets hot. The excess goes out the filler past the 13psi? pressure relief valve in the cap.
When it cools down, it sucks air back in (thru the vacuum break valve in cap) the result is when you check it cold, it's looking a bit low....
Important thing is- when it heats up next time it will merely displace this air back out the cap, so when it's hot it is actually full. But you can't see it.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

see even doc made what i said plasible ... wow big word
i'm right ha ha ha ha stick that in ya pipe and smoke it ... ok i'll settle down now
makka

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Anonymous moderation means the agro that is built up towards the mods isn't aimed at an individual (fewer "Makk" attacks). Less stress for mods means less moderator "retirements".

yeah, that is one of the 5 nails that has survived so far
but what about that beautiful clean and green coolant..? I thought that was impressive

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78 van 1300 cam extractors weber, 12" Superlights Metros Konis HiLos MP3 Amp Sub Alpine speakers and lots of fur
www.crazybitchracing.com