C70: Water Flush

[aegeandestiny]

Weather Permitting tomorrow i intend to flush the water out my C70 Coupe as it has been stood for a year and the water has gone unpleasant in the Water container in the engine bay, has anybody a link please as i cant find one on the web to step by step instructions please? Help would be appreciated. Thanks

[MikeS100]

I did this a couple of weeks ago following the advice from XRAY-CHARLIE-TWO here: http://www.volvoforums.org.uk/showthread.php?t=179169

It's time consuming because you have to give it a chance to flush all the old stuff out but not a big job. I had the thermostat housing open anyway and I was lucky to have a radiator drain plug so didn't have to remove the bottom hose, apparently some have them and some don't so hopefully yours is one of the ones that does as it makes it much easier as there is an access hole to the drain plug.

[rippedoffagain]

I don't know the specifics for your car, but in general the procedure is simple enough.

1. Find the hose clip holding the lower of the two fat hoses onto the radiator, and undo it.

2. Spill old coolant all over your boots.

3. Remove the filler cap on the expansion tank (the water bottle in the engine bay).

4. If you want to flush it thoroughly, stick the garden hose in the bottle and start it running while at the same time the engine is running, so that coolant spews from the disconnected coolant hose. Keep it running until it runs fairly clean.

5. Switch the engine off and give it a minute or two to stop dripping. Stick it all back together.

6. Pour new coolant in. There will be lots of air in the circuit now. There's probably a proper way to bleed it but my way is to grip the fat hose and repeatedly squeeze it in a pumping action. Lots of bumbles will come up in the expansion tank and the coolant level will drop as the air is dislodged. Keep topping it up and keep pumping until no more bubbles and the level stays right.

7. Start her up and leave her running while you have a cup of tea. The filler cap should still be off (allowing more air to escape). Check the level again, and top up if necessary.

8. After a few miles of driving, check the coolant level again. If its dropped, most likely its just burped an air bubble out, but it could also be that the hoses aren't reconnected nice and securely. It is essential that you know the hose is back on secure. My mate killed a car once when the bottom hose came off without him realising, spewing coolant out while driving, and allowing the car to overheat.

[aegeandestiny]

Thanks for the replies and the info

[Luxobarge]

Originally Posted by rippedoffagain

6. Pour new coolant in.

Note the use of the word "coolant". If yours had just water in it, as implied by your question, that's probably why it's in such a state. Water alone will kill the engine sooner or later.

[rippedoffagain]

Originally Posted by Luxobarge

Note the use of the word "coolant". If yours had just water in it, as implied by your question, that's probably why it's in such a state. Water alone will kill the engine sooner or later.

Well spotted, and very true. I once had a radiator burst. I forget to buy new coolant when I got the new rad, and figured I'd just fill it with water for now, then get some coolant, then drain and refill with said coolant. I never got round to putting proper coolant in. It was only about 6 weeks later when the water pump failed (possibly not my fault, but equally could have been), the engine overheated very, very much, and destroyed the cylinder head.

Coolant not only changes the cooling properties of the water, but also it contains anti-corrosion agents. Some of the gaps its expected to fit through are very tiny. It wont take much to block those channels up, so coolant is vital, not just water.