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

Yes Indeed, My current plus 4 feels quite heavy and pudding like when I think back to the CVH. The steering was much lighter and somehow more forgiving giving that reassurance allowing you to make adjustments on a micro scale through the corners that the current car doesn't!

Yes, my 85 CVH 4/4 was bar far the best Morgan I have ever had. It was pretty basic compared to the later trads. and seemed better balanced with the simple lever arm rear suspension. With light steering, nibble and never an issue with ground clearance, only down side some 40 years on is the short door ( that's more an issue for me in the intervening years).

Amazingly economical when cruising on the motorway, and whilst not as quick, was quite enjoyable and more chuckable down the country lanes. My ideal one would be late 80's/early 90's before EFI and catalysts, but with the now standard creosoting of the wood with a glavanised chassis and wings were sprayed off the car, so no cracking of paint over the .wing beading every time the chassis flexed leading to further corrosion between the panels.

John, you so correctly speak the truth. Just imagine such a car with all the alloy, stainless and galvanised chassis and a long door? Think I'd have one in a heartbeat! There's just so little to go wrong and you could sort it at the roadside if it did. Might like to add the Efi five speed box to it as an option and that for me would be utopia!

Mine had the 5 speed not 4 speed box.

That means that in 85 Morgan were using the rear wheel mark 5 box?

Mine was one of the early cars so fitted, they started to fit the 5 speed sometime in '84 from memory. Mine was the Sunday Times competition prize car, which was exceptionally well specified.and equipped.

Another really exciting video from me

I also took the opportunity offered by the significant idling time to fine tune my short term trims under the warm up phase, largely using IAT correction.



Today I'm flushing the system with more de-ironised water to completely remove all traces of the Prestone flush chemical, and the last of the old red coolant, when the rad drains with clear de-ironised water I'll make up my 50/50 mix of Prestone concentrate anti-freeze and de-irionised water.

Once filled with my fresh anti-freeze mix and I've fully bled the system, it's job done for the next 10 years

Here's what what I found in Monty, God only knows how old it was?



And here's an example of what I'm calling the 'wet clay' buildup on the roof of the header tank.



Now we can see the colour of what came out after using the Prestone chemical flush.



Theres clearly a lot of foaming agent in the flush treatment.



And now after much flushing with de-ironised water the sytem is running clean, all the old red coolant has gone, as has any residual flushing chemical.



Next up, here's the Prestone coolant going in, I had some pre-mix left over from working on my friend' Lotus Elan Plus 2 so I figured I'd use it for one last flush.



I'm nearly done, I just need to drop one last rad/header tank worth of what is now already largely the correct ratio of Prestone, and before I complete the final fill.

'Old Red' be gone

Thing is…Sewin said he only managed to get about 4 3/4 litres of coolant mix back in. So that is on top of the approx 5 litres of distilled water sitting in the engine. So the overall dilution rate is now approaching 25% rather than 50%.
Guess it would be wise to get the actual concentration scientifically measured after running for a while for peace of mind?

Not when my final fill is using the concentrate I specifically purchased for the job Deejay



The pre-mix was left over from another job, so as it was effectively free to me, I extravagantly used it for the last flush

I appreciate Prestone say their coolant is compatible with all other colours/types of coolant, but I wanted to be 100% sure all the old red [and likely tap water] was completely removed. So, after getting the rad running with clear and pure de-ironised water I just ran the 4 litres of pre-mix through that I had left over from the Elan job for good measure.

Here's what came out from that last luxury flush



Rest assured the final fill ratio has been carefully calculated, actually it's comically easy to calculate because the concentrate comes in a 4 litre jug. The truth is doing the last luxury flush with pre-mix just means there will have been some pre-mix left in the line and at the very bottom of the rad, the drain plug on my Mulfab aluminum rad is horizontal.

In summary, Monty is now running closer to 55% Prestone concentrate and 45% pure de-ironised water, it's the most accurate way I could fully ensure a completely safe mix of the two new elements.

And nothing else from the past

I'm confident what's in there now is just the following:

1. New Prestone coolant

2. Fresh de-irionised water

I'm happy with that