Coolant flush and refill

T

thespringfield

Member
Hi everyone,

Changing the coolant this weekend and was wondering if anyone had changed their coolant without using a pressure device to prevent airlocks. I'm not planning on using one but workshop manual specifies it so just thought I'd see if anyone else has had any problems before I start.

cheers,

M
 
Hi M
I have changed the coolant twice, once when fitting a new thermostat and when replacing the water pump during a cambelt change. A pressure fill device is not really necessary providing you subsequently run the engine up to temperature so the thermostat opens to allow complete circulation of the new coolant. Once any trapped air is purged from the system top up the header tank, taking the usual care when removing the pressure cap.
It helps to use demineralised water for the antifreeze mix, especially if you live in a hard water area.
If the old coolant comes out clean then flushing the system is not really necessary. It was essential in the old days when antifreeze did not contain all the corrosion inhibitors and systems used to rust and scale up internally.
If you decide to do it anyway, for propper flushing its best to remove the thermostat to allow full circulation round the cyl block and head

Cheers Spike
 
Thanks,

I intend to do it this once because I had a new radiator fitted last year by a garage who sub-contracted the work to someone else. I don't know if that person used the old coolant (I believe you're supposed to refresh coolant after rad replacement) or even if they used the proper stuff.

I think the coolant was an orange/red colour but it is more red since I topped it up a week or so back so I'm a bit iffy about it all. If I don't do it then it will just play on my mind and I really want to do as much as possible to help ensure the longevity of the engine.

Cheers,
M
 
I have ordered a Defa coolant heater but I'm not sure yet if I'm going to try to install it on my own or leave it to experts. They have quoted 250 e for the installation.

I'm convinced I could manage the mechanical fitting but I am scared having problems with the coolant circulation afterwards because I haven't done refill/air bubble removals before and I'm not sure what tricks are required. Is there a screw I need to open to release the air or how in principle I should make sure I have no bubbles in circulation?
 
Don't worry Jupis. Spike is right. If I remember correctly, there isn't a screw to release the air. You might have to take the car out for a drive though, to get the thermostat to open. Otherwise it could take forever :)
 
If you have a dehumidifier, you also have a source of demineralised water.

RAB
 
OK thanks, today I heard Defa has arrived to the garage now. There was another person in the phone and he said installation would be 60-70 e. If that is the case, I leave it to them :)

The cables to interior would be around 90 e + more expensive installation. I guess I try to figure out if I could avoid these expenses by doing it myself and, if possible, maybe not using original cables for that. :eek:
 
I have the engine heater installed now for my TDI. I'm thinking that this type of Defa heater might be rare among community members. Hopefully I'm not the only one, though :rolleyes:
 
No, I don't have the cable yet. :( I most probably just buy a second hand defa cable and install it myself during the summer.
 
You're on the right track. There are quite a few used or sometimes even new cables for sale on the used market, and you can get them for almost nothing.
 
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