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Coolant filling


25 May 2015
I am about to change the coolant in my 04 C2. Looks like it is the original material as it wasnt changed when the LTT was fitted.
I am thinking about using a vacuum filler to make it easier, has anyone got direct experience of using these and what make? There is a wide range available on ebay at all prices.
I use them and imho if you have drained out the radiators then they are invaluable !

Cars like Panamera and you cant bleed them without this tool .

we use a snap on version which causes a pretty good vacumn , some of the cheap ebay ones dont last long and struggle to get a good vacumn .. ive had some success with them but they fall appart pretty quick.

For a one off then it might be usefull ... they are pretty cheap.

The whole problem is air lock and there have been many discussions on how to get aroung that so ill not go into it .

I would vacumn and suck in the coolant .. i would then get someone to rev the car 2.5 - 3k rpm whilst i filled the bottle .. plenty of bubbles and if the person reving it lets the rpm drop you will have coolant every where !

So constant rpm , wait till its not as " bubbly " or aerated then screw the cap on quick.

R/T then leave to cool down overnight .. top up in the morning and jobs a good un !
When I replaced my engine, I had all sorts of problems. First attempt and I had an air lock - no heat from the heaters and temperatures starting to rise on the gauge. Thankfully I wasnt driving it, just trying to bleed it.

Now I think the biggest issue I had, was that I hadnt fully drained the system down without realising it. The amount that sits in the front is surprising even when you think its all out so my process now is to drain it level, then raise the front and raise the back independently so you are effectively tipping from all angles which got the vast majority out.

I then tried to use a cheap ebay vac tool which was utter rubbish - the caps that came with the kit were pretty good but the actual vac part that connects to the compressor was terrible and kept falling apart. If I bought one again - I would spend more and get a mid range setup like a Sealey or Draper which actually arent that much more.

I then slowly filled the system manually and it was absolutely fine this time. It wasnt much fun and I'd rather not have to do it again - maybe I was unlucky but it was certainly a learning curve.
Thanks for the replies everybody, a question for deMort, what do you mean by filling the bottle? Are you referring to the coolant reservoir or the bottle with the new coolant.
My explanations are never brilliant :)

I meant the coolant resevoir ..

Basically someone is reving the car at 3k rpm , you are pouring in coolant , it will froth a lot , wait till it settles and keep topping till its at the correct lvl then quickly put the cap on ... if they lift off then coolant will pour out the resevoir !

leave the car to idle ( heater on hot as you want hot air comeing out ) then tidy up... no hot air and you have an air lock .. best not to run it for too long at this point , let it get warm then switch off .

Give the car a run then leave it over night , check and top up the lvl in the morning
Thanks deMort, its the idiots you are trying to educate who are the problem!
A further question, if I use an effective vacuum filler I would assume there should be no need to mess around filling, revving etc except perhaps topping up over a few days to ensure complete fill?
Vacumn bleeders help a lot but you will still need to rev it to top up .. you can by pass this if you wish but you will have a certain amount of air still in it .

If bypassing this part then just leave it on lidle till its hot .. heater on hot then leave it over night top up in the morning , give it a run .. let it cool down then check .

You dont have to leave it over night but you aint getting the cap off untill its cooled down .

Without a vacumn bleeder you can get some very serious air locks and the car can over heat very quickly so i prefer useing one.

People here dont and have found ways around it , i have in the past .. but these days i prefer an easy life and not have to struggle with problems !

Btw .. its my explainations that are bad , at least im an average mechanic though :D
Its the easy life bit that appeals and if you are only an average mechanic God help the rest of us!
I'm sure I can speak on behalf of everybody who reads this forum that we very much appreciate the time and effort you put in to help us amateurs who try to look after our cars properly.

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