Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Changing antifreeze

I want to change the antifreeze on my 1994 plus 4 (T16 engine). My question is draining the system is easy enough but with the sealed system how do I refill? There’s a header tank with convention radiator cap, and the a cap on the radiator with a “do not remove” sticker. Do I top up with the radiator cap or just use the header tank? Any tips re bleeding the system?

The "Do not Remove" may refer to when the engine is hot. I was informed by my local trusted garage man to fill up the rad, not the header. This is a Kia but I presume the same applies, possibly.

Simple, fill the rad when cold, then fill the expansion tank to the marker. Drive as normal, but check the expansion tank level for a few drives, top to marker if needed.

Fill using the radiator. I would then run the engine with the heater on & cap off so you can top up as needed whilst the air exits. This should take a few minutes max during which it can help to flip the throttle.

Once happy the air is out, turn off the car. Put the cap on the rad & open the expansion tank. Fill the expansion tank to the level & close.

With both tanks closed go for a drive till the car is at temperature. Keep the heater open till you are happy it is working.

Then park up at home & let it all cool down. Then you can recheck the expansion tank & fill if needed.

By coincidence I've just come in from doing mine, a good opportunity after having to change the thermostat, also flushed the rad through. My procedure is pretty well as JohnV6 describes above, everything works perfectly now! Best of luck!

It can also help to flush the heater matrix.