Draining and flushing coolant system......

Dani_B19

Dani_B19

Audi-sports own special child.
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Off work thursday so i think im going to have a crack at fitting my new coolant bottle and thermostat but.
Whats the best way to drain the coolant system? Been told there's a drain off at the bottom of the rad on the passenger side! Ive had a look but cant see and havent got a clue on how to get to it! Any help?

Also id like to flush the system out. Whats the best way of doing it? Shoving a hose pipe into the coolant bottle and just let it run out of the draining plug at the bottom of the rad?

Cheers :).
 
My brother works at kwik fit they have machines that extract the coolant and insert new coolant. Dont know how it works but its not expensive at all
 
The drain is REAL easy to find - get your head under the car and look at the radiator, you'll see a black knurled piece of plastic that you just pull out towards the back of the car then turn the plastic about 45 or 90 degrees and the water will drain out the bottom of the rad. If you're doing teh thermostat too, it would be worth removing the stat, flushing the system with water (via the header tank) till it appears clean from the bottom of the rad. Then leave the stat out and fill the system with water again and run the engine for a minute to pump round and get all the old coolant out. Then just drain and fill with coolant (bearing in mind, there may be more water than coolant left as you can't drain it all)
 
So i just need to get my hand under the passenger side of the car and i should be able to feel it, can you see it from above or is it just touch and feel?
 
Its on the bottom right corner of the radiator, looking from the front.you cant miss it if you look.
Did mine yesterday and fitted my new coolant tank.
 
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So if i popped my head under id be able to see it? Just asking as its a bit dark togo out and look lol.
 
Hi, i'm thinking of flushing my coolant and fitting a new thermostat 2moro. Quick question, I know you cant mix the coolants with other coolants but once its flushed can I put any bog standard one in or does it still need to be that g12 stuff.

Dani_B19 did you manage to get yours done ok, did you come across any problems?

Allan
 
Audi clearly state G12 or equivalent so I'd stick with that, they are on G12++ now, about £8-9 from the dealers.
 
Didnt manage todo it jonesy, ended up re-piping and fitting new oil catch can that turned out tobe a right pain in the ****.
 
How much g12 will I need once ive flushed the system? you dont need to remove the bumper to get to the plug do you?

Many thanks

Allan
 
Thanks for the help, managed to get mine done the other day, plug was fairly easy to get to, had to remove some of the plastic covers underneith to access it, turn it 1/4 turn anticlockwise then pull forward and the coolant flowed out pretty quick. Also changed my thermastat and removed whatever coolant was in that area. Topped up with 2 bottles g12++ from dealer and used deionised water from halfrauds. Temp gauge now works a treat and sits nicely at 90c also my heaters in car are so much better, especially when clearing the screen!
 
Nope, its not mandatory if you don't live in a hard water area. If you do, just boil a few kettles of water and let them cool down and use that water
 
Im not sure to be honest, my friend told me normal 'hard' water can still contain chemicals that can damage the inside of the radiator. Could be nonsense but it was only 3 quid for a 5l bottle. Plus it says on bottle recommended for coolant systems/batteries/air-con systems.
 
My a3 8l appears to have like a undercarriage preventing me from getting a good look or feel for the drain plug for the coolant. Is that normal. I took it to a mechanic to replace the fluid and he did but now it's leaking and refuses to take responsibility...any help of how I can access the coolant drain plug would be appreciated
 
Mohammed Patel said:
My a3 8l appears to have like a undercarriage preventing me from getting a good look or feel for the drain plug for the coolant. Is that normal. I took it to a mechanic to replace the fluid and he did but now it's leaking and refuses to take responsibility...any help of how I can access the coolant drain plug would be appreciated
Click to expand...
You take the undertray off
 
Sorry stupid question, when refilling coolant, am I doing this through the coolant bottle or should I take off the top rad hose and fill? cant see a radiator cap and have a small leak atm.
 
through the expansion tank, I don't think you need to bleed these, just fill to the line, bring up to temperature, let cool and top up.

there may be some value in running with the cap off for a couple of minutes.
 
heater on full also.
sometimes they can be a pia to bleed up.
if you have vcds, look at engine, block 001 for temps and feel rad lower hose to tell when the stats opened
 
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