Radiator fluid change.

[jamesmatheson]

Hello everyone, how do I go about changing fluid in my radiator. Have bluecol and distilled water too refill. What is the process for emptying old out and refilling please.

[Tom W]

Do you have a photo of your engine bay, so we can see whether you have the series 1 style or series 2 style of cooling system.

The process is essentially the same for both though. There’s a drain point on the bottom of the radiator, and one on the LHS of the block, towards the back under the exhaust manifold. Depending on the age of the car, this may be a proper tap, or a bolt. Coolant should be drained with the engine cold. Turn the heater to hot, then drain the old coolant from both points. You might need to rig up some funnels to get the coolant out from the block drain and into the pan without soaking the frame and torsion bar. Don’t forget to close the drain points when it’s empty.

After that, refill with the new. I prefer to premix my coolant before filling, rather than just tipping in 50% of each. You need to note roughly how much you get out as if you can’t get the same amount or more back in, you’ve got an air lock somewhere. Parking the car nose up (before you start) can help prevent airlocks when refilling. When you’ve got as much in as you can, start the engine with the radiator cap removed. The level may drop, in which case add more coolant back to the correct level. Keep an eye on the level and temp gauge for the first couple of journeys afterwards. Also, check for leaks from the drain points.

Put whatever you drain out into sealed containers, until it’s disposed of properly. Antifreeze is toxic, but also tasty, to cats and dogs.

[AshM]

May I ask a supplementary question to this post?

During some work a year or so ago I was sent an incorrect radiator drain tap. It was too big for my radiator and visually looks like it would fit in the position that Tom references; under the exhaust manifold.

As a late S2 I know it was not fitted as standard.

So, questions... Will it fit and is it a useful addition to help draining?

thanks
Ash

[Tom W]

I fitted a proper tap to the block on mine. It makes it easier to drain the coolant into a funnel, and cleanly into a container. Useful if I want to keep it for re use, for example if it’s being drained only to remove the rad for access.

I did have to faff around with a couple of sealing washers though, as the tap pointed upwards when first screwed into the block.

[AshM]

Thanks Tom.

I will add the tap next time I change the fluid.

Appreciate the feedback.

Cheers
Ash

[ETTony]

TBH I found that both my new radiator and block drain valves leaked, poor reproductions. So mine have brass plugs.