winchman

Active Member
Just discovered the coolant in my newly purchased Disco 300Tdi is too weak.
So I am going to refill it with the red long life stuff, so best way to drain fill and flush please?
 
Done loads of changes on my 300tdi. After a silly amount of coolant problems.

Take the caps off the radiator and thermo housing,
Remove the cap from the expansion tank,
Fill the radiator,
Put the cap on the radiator,
Fill the expansion tank until the coolant comes out the thermo housing cap,
Replace the thermo cap,
Pump the pipes a few times, you should see the coolant level rise and fall,
Start the engine and leave running for a few minutes,
With the engine running, pump the pipes a bit more,
Replace expansion tank cap,

Should be fine after that. Take it for a run and check the temp and level.
 
But what's the best way to get it back in?
I also have a Mazda Bongo so do suffer from Air Lock Paranoia.



Take off the screw caps on top of the radiator and the thermostat housing, commence re-filling via the header tank until the radiaotr is completely full then cap it.

Now cap the header tank and top up the thermostat housing until it starts to overflow, the cap it.

Now remove the header tank cap and verify that the level of cooland equalls the tank seam height. Then cap off.

Once that's done, start the engine and allow it to tick over until normal operating temp is achieved, then CAREFULLY remove the header tank cap and check the coolant level.

Keep a careful eye on the level for the following few days to ensure all the air is out. Then you're done !

Dave
 
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Thanks but if I pour it in the thermo housing it fills the expansion tank as this looks to be lower down?
 
Thanks but if I pour it in the thermo housing it fills the expansion tank as this looks to be lower down?

That's why I said "cap the header tank" - if you do this, you can fill up the 'stat housing without filling the header tank.
 
Thanks, but when I changed the thermostat it just filled the header tank when I filled the stat housing?
 
it will.

fill the rad till the tank is at the correct level, then fit the cap on the tank. continue filling rad till it is full, put plug in and then fill the thermostat housing. fit a rad bleed plug to the stat housing, so that it can be bled when hot and under pressure.
 
Excellent news. Just keep an eye on the level for the next few days and she'll probably burp out some air and the level might go down.

Cheers and Merry Christmas to you,

Dave
Will do wont be using it for a few days so will take it for a run and check it again
Have a good Christmas
 

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