Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Coolant system flush and antifreeze change.

What heater valve I thought the heater was always fed and heat controlled by flaps ? Pics if you have one.

Dave: Thanks for reporting back. Well done with the steradent treatment.
I have in the past, cleaned out screen washer bottles by chucking a handful of pea gravel in, with a cup of water and giving it a good swirl. Having not closely studied the baffle arrangement, would that work on the header tank or is it likely that either the gravel wouldn't reach all the parts…or if it did, it may be difficult to get it out again?
BTW, the comment from Keith about heater valves, I agree with, especially on +4 s from this era. Flaps are the only heat control.

The baffles will certainly be an issue for you mate as they even make rinsing out loosened debris from the tank tricky, I really wouldn't waste your time with pea shingle or similar, boiling water and Steradent tablets are definitely the answer.

Actually, if I was starting again I'd probably just buy a new tank.



Given how cheap they are I did order one as a spare just in case I couldn't get Monty's original tank up to my OCD standard
However, I needn't have bothered as I'm super happy with how my original came up with the Steradent treatment, I'll now being laying down the new one in my spares store.

I do get the heater is on a flap arrangement rather than a traditional valve but I like to feel heat all the same, largely because I'm old school but also as it still proves the heater core has a solid column of coolant running through it.

As I say, I recommend we all take a look at our expansion tank condition as mine was in urgent need of a clean, so it's safe to assume others will find the same. In keeping with my policy of base lining Monty's maintenance schedule, I'm confident my flush, tank clean, and fill with fresh Prestone antifreeze and pure de-ironised water will now keep Monty's cooling system in tip top condition for the next 10 years

The before...







And the after....





I hope you all agree, the above images speak for themselves?

All spot on dave. yes it's not a A series engine with water shut off to matrix but you need to know that you are getting coolant flow adequately through the heater matrix and with the heater control to max you can feel thermostat open and closed at the matrix. Interesting point, I asked ford for a header tank and they said .... not available however Land Rover Td5 disco's have it fitted and they are available there but funnily not through Morgan. Liked your pipe link for cleaning and next time I will definitely be visiting boots for the tabs!

\have to say you're not alone having fun with that bloooody cap... my god I thought I was on the generation game!... nearly threw it!

Observation!

Coolant level at hot idle, the coolant has fully expanded here.




Coolant level with engine speed raised to 2,000rpm and above, this is perfectly normal and is exactly what you'd expect to see on any car as the water pump gets to work.




Coolant level after switch off with the coolant temperature now at 70c, as we can see the coolant has already started to contract.



Now look closer and you'll see a small body of coolant has beed left trapped up top in the expansion tank, and on what is effectively a ledge, also note the condensed coolant droplets on the roof of the tank. This trapped coolant and the condensed droplets are what contributed to Monty's sludge build up in his sealed plastic expansion tank, it' also why 90% of the sludge I found was concentrated up top on the roof of the tank.

This is not a massive issue if like me you use your Morgan regularly, as at least the small amount of coolant trapped up on that ledge will be mixed back in with the far greater volume of coolant each time the car is driven, the advanced additive pack in the quality Prestone atifreeze can then get to work keeping sludge build up at bay, and any that does form will be held safely in suspention.

However, the truth is most don't use their Morgan very regularly at all, so with all that inactivity expansion tank sludge build up will inevitably start to become a real problem. In this respect, Monty's lack of use before I took him on was far from ideal, this is why its been so important to me to replace all his fluids with new.

Monty religiously enjoys an annual engine oil change, I also changed the gearbox and diff oils recently and the brake and clutch fluids were refreshed just a couple of weeks ago. He has now had a full coolant flush and change to Prestone mixed with de-ironised water rather than mineral rich tap water, and he really needed it too.

It also concludes my objective to baseline Monty's maintenance shedule, I can now follow a strict servicing shedule from fully confirmed starting points. A Morgan isn't just an artistic masterpiece to be admired in your garage, it's also a machine, machines need maintenance but they also like to be used!

What I'm trying to say is...

"Regular servicing asside, the very best thing you can do to maintain a long opperating life of your beloved Morgan, is simply to drive it"

And surely, that's the most fun part of Morgan ownership too

Dave, Thanks for all that.
Incidentally, I notice that you still have the OEM plastic tee piece on the bottom hose from the header tank. One or two people on here in the past, have had that break off and/or leak without warning.
You probably dont want to dismantle again but might be a good idea to add a spare one in stainless steel to your tool kit as a future proof.

Cheers, I'll get one ordered up.

Aluminium is probably best given the engine is also aluminium, and replacement should be straightforward using my hose clamp

Thanks, Dave.

Yes I changed my T piece for an alloy option after hearing about all the sudden failures some were having. It's a 16mm all round spigot size and seals ok but an 18mm might be a better fit if available?

Dont know why I said stainless…I actually used an aluminium one from Viper performance. I went for the 16mm barbed version and it wasnt quite the tight fit that I would have liked. However, it’s been there now for a couple of years with no leaks. Sewin’s suggestion of 18mm might be better but not easy to find.

Is this what you're looking for ?
www.ebay.co.uk/itm/184627867597