Coolant change

I am going to change the coolant this weekend (finally getting around to it after having a hard pipe to fit for almost a year!) and have a quick question.

To flush the system from previous threads it seems I just put a hose through the rad and block a few times, then fill from the top pipe and rad top.

Firstly, how can I make sure I get all the water out as I don't want tap water in the system.

Secondly, to get air out the system you would usually squeeze the top pipe but with a hard pipe....how do you do that?

Thanks

24 minutes and no replies, slacking people.

Its deffinately a 2 man job, it pisses out everywhere! I flushed from the top till the water was clear and repeated for the bottom which was a bit tricker. Do you still have the coolant expansion bottle on place? I thought that should sort the trapped air issue?. I wouldnt worry about any tiny bit of trapped water.

I don't think you'll get *all* the tap water out unless you have specialist equipment. I wouldn't worry about it.

As for airlocks, they can be tricky. I had to fill the system via the matrix pipes near the bulkhead: not easy.

hmmm. I thought it would be simple. Drain, flush, fill. done.

Seem like it is harder than that.

I do have the overflow bottle in place, but that doesn't really take care of any kind of air issue does it? just too much fluid, and the problem would be not enough fluid.

Its easy enough to do, fill up via the radiator, leave the rad cap off, start the car and get it to normal running temp, when its there the thermostat will open allowing the coolant around the engine and through the matrix, set the heater to max hot with the fan on, keep topping the rad up as required, it will bubble over as the air escapes, run engine until no more bubbles, you can raise the revs up to approx 2000 rpm which will help move any airlocks but will blow out some coolant, top up and check no more bubbles, fill the expansion tank approx half way.

Check the air coming out the vents in the car is nice and hot, if not you have an airlock so raise the revs to shift it and top up the rad, replace rad cap

Its easy enough to do, fill up via the radiator, leave the rad cap off, start the car and get it to normal running temp, when its there the thermostat will open allowing the coolant around the engine and through the matrix, set the heater to max hot with the fan on, keep topping the rad up as required, it will bubble over as the air escapes, run until no more bubbles, you can raise the revs up to approx 2000 rpm which will help move any airlocks but will blow out some coolant, top up check no more bubbles fit rad cap and fillexpansion tank approx half way way

spot on mate

spot on mate

Just to add, theres no need to squeeze the top rad pipe

will starting the engine blow coolant out to begin with? or do I start it with the cap on and take it straight off before pressure builds up?

will starting the engine blow coolant out to begin with? or do I start it with the cap on and take it straight off before pressure builds up?

If you've flushed it through with a hose pipe and drained all the water out then your system will be empty, fill the system with as much coolant as you can get in it, (just up to the rad neck) leave the rad cap off and start the car, you will get a bit of coolant coming out the top of the rad as the temp rises but not silly amounts, leave the rad cap off during the whole process as posted above

perfect, thanks Dunk!

No problem when your happy its all bled up and the heaters nice and hot you can pop the rad cap on, dont forget to top up the expansion tank.

Also worth checking for air after you've driven it around a bit with the heater on hot, but let the car cool down 1st as it'll be under pressure and rather hot !!! how olds your rad cap ? if its old it might be worth getting a new one.

do you fill the expansion tank up to the fill line too? I thought that was just a kind of overflow.

do you fill the expansion tank up to the fill line too? I thought that was just a kind of overflow.

Fill it to the top level, as the coolant heats up it expands forcing it out the rad cap through the overflow, as it cools it contracts drawing coolant back in.