I am having major problems with air in the cooling system. The hose from the head to the inlet of the heater blew about 3 weeks ago, an since then i have had problems with high engine temps. So i want to completey drain the system and start again. whats the best way to refill making sure all of the air is removed. i dont mind if it takes 2 - 3 hours to do, as long as i can do it properly, no shortcuts !!!
Edit: soz about posting in wrong section, wasn't watching what i was doing, i should know better, being a former mod of a forum....
Advice on draing / refilling cooling system
Moderator: martauto
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kam-325i
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Andy_magic
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My advise would be to drain the system completely by either the drain plug on the rad if fitted or by taking the bottom hose off.
I would then flush the system out with a hose pipe running water both ways round the cooling system.
Once it's flushed out, put all hoses back on securely and get some fresh coolant. Fill the header tank as far as you can and then open the bleed valve on the thermostat housing. Make sure the heater control is set to its hottest, this ensures coolant flows through the heater matrix.
Sometimes the heater can be a hassle to bleed, my preffered method is to squeeze the hoses repeatedley to help pump airlocks out of the system, the rad cap and bleed valve will need to be shut to do this.
Once you are happy that the heater is working, fill the header tank right to the brim and crack open the bleed valve on the thermostat housing again and leave open until a constant flow of coolant comes out with no air bubbles.
Hope that helps
I would then flush the system out with a hose pipe running water both ways round the cooling system.
Once it's flushed out, put all hoses back on securely and get some fresh coolant. Fill the header tank as far as you can and then open the bleed valve on the thermostat housing. Make sure the heater control is set to its hottest, this ensures coolant flows through the heater matrix.
Sometimes the heater can be a hassle to bleed, my preffered method is to squeeze the hoses repeatedley to help pump airlocks out of the system, the rad cap and bleed valve will need to be shut to do this.
Once you are happy that the heater is working, fill the header tank right to the brim and crack open the bleed valve on the thermostat housing again and leave open until a constant flow of coolant comes out with no air bubbles.
Hope that helps
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kam-325i
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Cheers for that, i shall give it a go
When you say "squeeze the pipes", which pipes ?
When you say "squeeze the pipes", which pipes ?
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Brianmoooore
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If you want to drain the system completely, then you have to undo the block drain plug as well. This has a 19mm hex head, as is near the rear of the engine, under the exhaust manifold. If you do remove and replace it, then don't expect to have too much skin left on your knuckles afterwards.
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tourer-dan
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Yep Brian's right - it's under cyl 5 and is virtually inaccessible with anything snap on has to offer........
*when* you get it out, replace it as half of it will probably be dissolved, they are about 30p from the dealer.
As you fill the system, fill it slowly until the header tank is full, then massage all the 'big' pipes repeatedly. the level should drop, so keep topping up. Once you're satisfied, run it up with the tank cap on (with the heater set to hot). Loosen the bleed screw on the top of the thermostat housing until fluid free from bubbles runs, then do it up. repeat a few times. Feel round the back of the head to the elbow (the one which you've just had blow) and rev the car to 3000rpm for a few seconds until you can feel it nice and hot, then feel the heater outlet pipe from the bulkhead and make sure that's getting hot too. Keep bleeding at the thermostat, and massaging the hoses. Keep your eye on the fluid level in the tank.
To be honest, when I did mine for the first time I was expecting some long drawn out drama, but it was no worse than any other can really.
all the best.
*when* you get it out, replace it as half of it will probably be dissolved, they are about 30p from the dealer.
As you fill the system, fill it slowly until the header tank is full, then massage all the 'big' pipes repeatedly. the level should drop, so keep topping up. Once you're satisfied, run it up with the tank cap on (with the heater set to hot). Loosen the bleed screw on the top of the thermostat housing until fluid free from bubbles runs, then do it up. repeat a few times. Feel round the back of the head to the elbow (the one which you've just had blow) and rev the car to 3000rpm for a few seconds until you can feel it nice and hot, then feel the heater outlet pipe from the bulkhead and make sure that's getting hot too. Keep bleeding at the thermostat, and massaging the hoses. Keep your eye on the fluid level in the tank.
To be honest, when I did mine for the first time I was expecting some long drawn out drama, but it was no worse than any other can really.
all the best.