Morris Minor Owners Club

Hello
I have a 1952 mm
I have had the radiator brazed and pressure checked, and all is now fine after a coolant leak.
My question is regarding the header tank. If i leave the engine idling from cold for about 20 minutes, the header tank will become too hot to touch - is this normal?
Also, i am hearing bubbling noises from around the cap, however no liquid is emerging, and also when i press down on the cap, the noise ends - is this something to be concerned about?

Many thanks

Hi,

My header tank gets really hot as well. I dont think you should be concerned.

However, you might consider changing the radiator cap though if you can hear air escaping.

Best of luck,

Karl. (South Wales Branch - Series MM 1952)

IIRC, the cap is rated at 4psi so when it heats up and the air expands it will pop off at 4psi to keep the rad from bursting.

Do you have a fan on the dynamo or a waterpump?

Thanks for this Karl.
I will try and source a new cap. It is not the original radiator, but one that looks circa 1960s (marston)

Cheers

Tony

Thanks Rob.
There is no water pump - just a fan.

Have you got a thermostat fitted?
Is the bottom of the rad cold?
It is probably not a good idea to leave the engine running at tickover for a long period as the fan will not be drawing much air through the rad, particularly on a hot?? day. Having said that I have run my engine without water pump or fan for a two week period without it overheating. However I did have a temp gauge

Hi Mike
No water pump.
How can i tell if I have a thermostat ie. where is it located, and what does it look like?

The thermostat is under the thermostat housing at the end of the top hose.

Hi Tony,

My sidevalve doesnt have a water pump either, I also dont have a temp gauge. It is a bit of a worry on really hot days but saying that the bottom hose always seems to be quite cool. Only on really hot days do I think about it really. Maybe you could get a temp gauge fitted if your worried? It would give you peace of mind.

Karl.

Next question will be "Where do I fit a temp gauge sensor?"
If anyone wants to know just ask

Hi Mike
Yes - that would be useful to know.

The sensor can be mounted as low as possible in the radiator header tank, the one in the photo is too high[frame][/frame]
Or on the later heads the circular boss in the head, adjacent to no 3 spark plug can be drilled and tapped
[frame][/frame]
The Smiths Gauges are available with a magnolia face which matches the existing gauges and electric or capillary
[frame][/frame]