Diesel cooling system

[mgdavid]

Went to flush and refill my newly-acquired TD estate this evening - the book says capacity 15 pints but on draining via the bottom hose it would only take 7 pints to full again - is this normal ? is there really that much in the block and heater circuit? Any tips on completely draining it? :banghead:

[dutch-van-driver]

Hi,

I've had to change the cooling fluid a few times and was never able to extract all fluids from the car. There isn't realy a nice lowest point on the block to extract it all. At least not to my knowledge. All instructions on getting all fluids out are also releasing the bottom hose of the radiator.

I would alos like to hear of another way (if there is a nice possibility to do this).

Marc

[e692wtt]

What I do on my Monty (1.6 Petrol engine) is this...

Remove the expansion tank cap, and also disconnect the heater hose that runs from the thermostat housing to the back of the engine bay at the thermostat housing. Some coolant will run out, this is ok.

Put a running hosepipe (or a watering can is fine, just it needs refilling lots of times) into the expansion tank and pour water in. If you put your finger over the end of the heater hose, this will flush the engine out and replace the old coolant with water. If you then hold your finger over the pipe on the thermostat housing that the heater hose goes onto, this will flush out the heater and replace the old coolant with water. It is worth allowing the water to run through the engine and heater like this for fifteen minutes (or more) until the water coming out is clear-looking. If you reconnect the heater hose to the thermostat housing temporarily, you can flush out the top hose, if you feel this is necessary (assuming the top hose is lower than the top of the expansion tank).

Then make sure the heater hose you have removed is as full of water as you can and refix it to the thermostat housing (this may not be easy but you can bleed the air out later if the heater doesn't work properly).

Remove the water supply from the expansion tank and remove the bottom hose (as you have done before to drain the coolant) until the water stops draining out. Hopefully there are now about 8 pints of water in the engine.

Refix the bottom hose and add antifreeze to fill the engine. Hopefully (again) this will mean 7 pints of antifreeze to give you a mixture of just less than 50% antifreeze in your engine (should be just over 46% if you add 7 pints exactly of antifreeze to 8 pints exactly of water) to give good protection for 2 years.

You can bleed the heater hose (where it joins the thermostat housing) as the engine gets nearly full of antifreeze, and you *should* only lose water at this point (while bleeding) as that is what the hose contained after flushing (but a bit of antifreeze may be there as well).

Make sure all hose clips are tight and there aren't any leaks of your new coolant, start the engine, make sure the heater works and that there aren't any coolant leaks as the engine warms up, and that's it all done! :)

[e692wtt]

This is additional to the previous post (by me), but the 'edit reply' button seems to have gone AWOL again... :confused: no, it isn't on any of my posts at the moment.

Instead of (3rd paragraph):

Put a running hosepipe (or a watering can is fine, just it needs refilling lots of times) into the expansion tank and pour water in. If you put your finger over the end of the heater hose, this will flush the engine out and replace the old coolant with water. If you then hold your finger over the pipe on the thermostat housing that the heater hose goes onto, this will flush out the heater and replace the old coolant with water. It is worth allowing the water to run through the engine and heater like this for fifteen minutes (or more) until the water coming out is clear-looking. If you reconnect the heater hose to the thermostat housing temporarily, you can flush out the top hose, if you feel this is necessary (assuming the top hose is lower than the top of the expansion tank).

I *should* have written:

Put a running hosepipe (or a watering can is fine, just it needs refilling lots of times) into the expansion tank and pour water in. If you put your finger over the end of the heater hose, this will flush the engine out and replace the old coolant with water. If you then hold your finger over the pipe on the thermostat housing that the heater hose goes onto, this will flush out the heater and replace the old coolant with water. It is worth allowing the water to run through the engine and heater like this for fifteen minutes (or more) until the water coming out is clear-looking.

Reconnect the heater hose to the thermostat housing temporarily and remove the top hose from the radiator, and you can then ‘reverse-flush’ the radiator by adding water through the expansion tank. Again, do this until the water from the top pipe on the radiator is running clear.

Edited because the bit about the top hose is nonsense, but the radiator will need bleeding as well. :giveup: It all makes sense if you remove the third paragraph of my previous post and replace it with the two paragraphs I have just written while cutting and pasting it into 'Word' to print it though... hopefully. :)

Lack of 'Edit Reply' Button - is this so that people can't alter their posts at a later date (ie once they have logged off from the session they posted in?)t to allow continuity?

[mgdavid]

many thanks Rich, that all makes sense. Off to do it now! :)