Series MM overheating?

[yme402]

Hello
I have a 1952 series MM with the 918cc sidevalve.
On returning from a good 20 mile run, I noticed a small amount of water coming out of the overflow pipe. Is this normal, or does it look like a cooling/headgasket issue ?(never had any issues here before).

On a similar subject, any advice on draining the radiator would be much appreciated. The handbook shows a tap at the bottom of the radiator to drain it, however mine does not appear to have one. SHould i just disconnect the bottom hose?

thanks

Tony.

[moggiethouable]

Just changed the radiator cap on mine and cured the same but possibly more dramatic leak on my 1098.
I flushed out the rad by disconnecting the lower hose and pouring water down said open top of rad.
The cap was old and sticking at an angle and jamming open, do make sure you get the same length cap, if its shorter it will of course not seat.
The pressure rating will be stamped on the cap,4lb at a guess, its only a 2-£3.00 fix so a good place to start.
Use blue anti-freeze not red,year round, as it helps as an anti corrosion media.
So endeth the lesson, Amen

[yme402]

many thanks for the sermon!
do you use deionised water, or good old corporation pop?

[moggiethouable]

many thanks for the sermon!
do you use deionised water, or good old corporation pop?

I have used tap water, but have always been intrigued by the statement in the Leyland Manual that suggests rain water
Of which here in the North East we have a plentiful supply thanks to Kielder reservoir not supplying the new "white heat" second coming of the Industrial revolution.

[mike.perry]

You may well have overfilled the rad. If you poke your middle pinky in the top of the rad, not recommended when it is overheating, and the water comes up to the first knuckle, that is about ok.
Are you running with a water pump?

[yme402]

Hi

Many thanks guys for all the advice.
I have checked the levels - seems fine.
Decided to fush, and drain via bottom hose, as i fear coolant not changed for 10 years or more.
Noticed a pin hole in top of radiator - is radweld a good solution here?

Also, now radiator is drained, water still left in looking through the cap - does this look like a blockage, and if so whatis the best remedy?

[mike.perry]

The water you can see is sitting on top of the core plate.
I would remove the radiator completely, two bolts each side, 1/4 Whit spanner, although you may have trouble releasing the top hose. You can then turn it upside down and flush it through with a banned hosepipe and shake out any sediment. Whilst the rad is out you can repair the hole in the header tank and fit a drain tap. Do nor use Radweld or any radiator "repair" as it blocks the core. If you have a water pump you should open the block drain tap and make sure that the block is free of sediment

[yme402]

Hi Mike
Many thanks for this

I will remove the radiator, and repair the split at the same time with some radiator repair putty.
The split is where the header tank meets the main part of the radiator, and looks like it has possibly been repaired there before.

With regard to radiator removal, It seems near impossible to disconnect the top hose - any tips here?

Thanks again

[bmcecosse]

" radiator repair putty. " Oh dear.......

[mike.perry]

It depends how good your thermostat housing is. If it is ok then unbolt it, remove the rad and then remove the housing from the top hose or just leave it attached.
Clean up the face and replace it with a new gasket as you slide the rad back in.
Once you are happy that there are no leaks add plenty of antifreeze to prevent corrosion of the alloy parts of the engine.
If you post on the Series MM message board you will get replies from other Series MM owners who are familiar with Series MM problems.

[yme402]

Had the radiator professionally brazed, pressure tested and re fitted it, and is good as new.
Tip about pouring boiling water over top hose is a great one - made connecting and dis-connecting a doddle!

Thanks for the advice guys!

[bmcecosse]

That's a better repair.....you can sleep easy now.