changing coolant?

ScoobyDoo69 · 29 Oct 2006 at 12:28

need to do anything special?
I planned to drain it, fill with water, drain it, fill with water and drain it. Just to clean it out, and then put water + coolant. Run it for a bit, let it cool down, pour more coolant in, and a touch more water until full?

I don't have to do anything else do I?
cheers

ScoobyDoo69

Scania · 29 Oct 2006 at 12:31

ScoobyDoo69 said:
need to do anything special?
I planned to drain it, fill with water, drain it, fill with water and drain it. Just to clean it out, and then put water + coolant. Run it for a bit, let it cool down, pour more coolant in, and a touch more water until full?

I don't have to do anything else do I?
cheers

ScoobyDoo69

I'd ask on a dedicated scooby forum to be sure mate, but, what you say sounds ok.

-westy- · 29 Oct 2006 at 12:33

instead of filling it up, maybe just drain it, then stick a hosepipe in the header tank and let it flush through

ajgoodfellow · 29 Oct 2006 at 12:41

Don't you have to bleed the system to ensure that there isn't any air caught inside it?

Guv · 29 Oct 2006 at 12:51

I did mine yesterday.
I drained it, filled up with water, drained it again, filled up with water, went for a quick drive to get it hot and mix around, drained it when cool, filled with water, drained it again, then filled with antifreeze+water.

I just guessed

ajgoodfellow said:
Don't you have to bleed the system to ensure that there isn't any air caught inside it?

I think if you pour the water in very slowly then you should be ok

Saytan · 29 Oct 2006 at 13:02

on my peugeot engined rover, so may not apply here, but the following needed to be stuck to

make sure the bleed screws are open when filling.
make sureheater controls on the dash are set to full hot.
fill slowly.
drive gently for 10 miles or so with a big bottle of pre-mixed coolant to hand

Tesla · 29 Oct 2006 at 13:07

Guv said:
I did mine yesterday.
I drained it, filled up with water, drained it again, filled up with water, went for a quick drive to get it hot and mix around, drained it when cool, filled with water, drained it again, then filled with antifreeze+water.

I wouldn't recommend pouring cold water into a hot system, any plastics are likely to crack/fatigue.

EDIT- Just re-read your post and it sounds as if you DIDN'T fill it with cold water when hot? Still, worth noting my post as it may save someone somewhere!

Guv · 29 Oct 2006 at 13:10

Tesla said:
I wouldn't recommend pouring cold water into a hot system, any plastics are likely to crack/fatigue.

EDIT- Just re-read your post and it sounds as if you DIDN'T fill it with cold water when hot? Still, worth noting my post as it may save someone somewhere!

I didn't

I waited for it to cool down 1st. It's a good point though, could cause a lot of damage.

Lashout_UK · 29 Oct 2006 at 13:50

Best use distilled water as well, instead of tap. It's negligible but tapwater does carry a lot of contaminants/crud that generally does not do any good, over a period of time.

It's more applicable to classic engines (hence me doing so) but anything that helps your engine is a good thing in my eyes

ShakenNstirred · 29 Oct 2006 at 14:18

Lashout_UK said:
Best use distilled water as well, instead of tap. It's negligible but tapwater does carry a lot of contaminants/crud that generally does not do any good, over a period of time.

It's more applicable to classic engines (hence me doing so) but anything that helps your engine is a good thing in my eyes

yeah i always use distilled water and coolant, i`d never use tap water

James_N · 29 Oct 2006 at 15:08

Ive gotta drain my system and add coolant. Had a split pipe last week, so just for quickness, i chucked tap water in. Gotta drain it, and add water + coolant sometime this week.

Ive always just topped all my cars up with tap water, so do my mates, never had any problems.

Zip · 29 Oct 2006 at 15:20

Lashout_UK said:
Best use distilled water as well, instead of tap. It's negligible but tapwater does carry a lot of contaminants/crud that generally does not do any good, over a period of time.

It's more applicable to classic engines (hence me doing so) but anything that helps your engine is a good thing in my eyes

Wjhere do you get Distilled water from?

Is it hard to make it yourself?

MuvverRussia · 29 Oct 2006 at 17:36

way I do it is to drain it (either drain plug or take off bottom hose) then fill with coolant and start the engine with the radiator cap off, run it for 2-5 minutes to purge any air in the system out. Works for me.

Distilled water is cheap enough to buy, wouldn't bother doing it DIY.

timbob · 29 Oct 2006 at 17:42

Surely there's no need to drain it and refill it a handful of times? Just drain it out once, unscrew the thermostat housing and take the thermostat out, put it back together again, then stick a hosepipe in the top hose (against normal flow) and backflush it all out until the water runs clear.

Then put the thermostat back in, locate all the bleed screws, fill up with coolant until you get a solid stream of fluid out of the bleed screws in turn, before shutting them one by one.

I think most engines are self bleeding, so run the engine with the cap off the tank and all the air will bubble out - hey presto, no air locks.

Mickey_D · 29 Oct 2006 at 21:23

timbob said:
I think most engines are self bleeding, so run the engine with the cap off the tank and all the air will bubble out - hey presto, no air locks.

Until you get into cars like the Saab 900 and any mid-engined car with the radiator in the front. Then there are bleeder nipples in the system due to the radiator being lower than other components in the system.....

PeterT · 29 Oct 2006 at 22:23

You could use the water that is collected from a condensing type of tumble drier. It has evaporated from the clothes and has been condensed again without the hard water deposits and pumped into the tank. Nearest thing to distilled water, especially if you live in a hard water area.

PeterT

Clarkey · 30 Oct 2006 at 00:32

get it from halfords about 3 quid for 5 litres, should be enough for most applications.