Changing coolant advice

[s4rap]

Hi all, I'm thinking of changing and flushing coolant in my clk430, could anyone give me some pointers? Not sure about bleeding and is flushing a good idea? Thanks

 

[Nasco12]

I believe the correct way to do it is to drain from the radiator (easy) and the block (difficult). Otherwise you'll have to stuff the garden hose down the reservoir until the stuff that comes out the radiator runs clear.

 

[s4rap]

Thanks,I was thinking of draining the radiator,top up with water,run engine warm to flush the heater system. Then let it cool,drain again and then add antifreeze and water 50/50 mix.is it a good idea to flush with hose or use one of those radiator flushes?

 

[Dieselman]

As said, just open the block drain.

 

[s4rap]

Is it ok to flush the system with the hose whilst the engine is running? Thanks again!

 

[Nasco12]

Thanks,I was thinking of draining the radiator,top up with water,run engine warm to flush the heater system. Then let it cool,drain again and then add antifreeze and water 50/50 mix.is it a good idea to flush with hose or use one of those radiator flushes?

That's more or less how I did it. But remember when you have flushed the system there will still be a considerable amount of water (with a tiny amount of coolant) left in the block. So the mixture you prepare has to take account of this.

In my case the coolant capacity is 9l or thereabouts so I added 4.5l of MB coolant and then topped up with water, working under the assumption that the two will mix together perfectly in the long run.

 

[markjay]

Is it ok to flush the system with the hose whilst the engine is running? Thanks again!

In the olden days this was considered a no-no that was said to crack engine blocks and heads.

Never tried it so I can't comment....

In fact you were not even supposed to fill-up a hot engine with cold coolant, let alone flush with cold water.

The procedure was:

Warm engine to working temperature.

Drain old coolant.

Wait for engine to cool down.

Refill with fresh coolant (or flushing mixture and repeat process) etc.

 

[s4rap]

Thanks for replies,I'm going to change all the fluids whilst car is offload over winter so more questions on way!

 

[flango]

In the olden days this was considered a no-no that was said to crack engine blocks and heads.

Never tried it so I can't comment....

In fact you were not even supposed to fill-up a hot engine with cold coolant, let alone flush with cold water.

The procedure was:

Warm engine to working temperature.

Drain old coolant.

Wait for engine to cool down.

Refill with fresh coolant (or flushing mixture and repeat process) etc.

^ Exactly what he said. Hot engine + Cold water or topped up with cold coolant = recipe for disaster.

Drain hot, flush cold, fill cold.

 

[ivandraganov]

Happy ester everyone,just wonder has anyone used non toxic antifreeze,the one for central heating that Screwfix sell,in your car,cheers

 

[Scott_F]

Happy ester everyone,just wonder has anyone used non toxic antifreeze,the one for central heating that Screwfix sell,in your car,cheers

Why would you ?

Antifreeze for cars is widely available !

 

[ivandraganov]

Why would you ? Antifreeze for cars is widely available !

For environmental reason,don't wan't to poison anybody..