TD5 coolant restrictor

New radiators come with a restrictor to be fitted into the fuel cooler, does anyone know why or what happens if it’s not fitted? I had a new radiator nearly two years ago and found this in the cab today, wondering if that is why I’m getting coolant coming out the cap (which started around the time the radiator was changed)

The restrictor is to be fitted within the old style fuel cooler (pre MY02 vehicles) and per LR is to 'improve durability of the radiator'...
See the accompanying TSB.

MTurri said:

The restrictor is to be fitted within the old style fuel cooler (pre MY02 vehicles) and per LR is to 'improve durability of the radiator'...
See the accompanying TSB.

Click to expand...

Thanks, yes I’ve seen it but it doesn’t fully explain what it does.