expansion tank

[cvw 0]

just about to replacemy expansion tank and fan switch was wondering whats the best way to drain the system and refill it again without any airlocks? thanks wes

[nocrap 0]

My way........

 

1.Remove tank or New tank cap

2. Disconnect bottom rad' hose

3. Allow to drain into a big tray/dish

4. Wiggle pipes to remove any remaining water

5. Reconnect all

6. Fill with G12+ coolant mix

7. Squeeze coolant pipes

8. Top up expansion if required

9. Start engine with cap still off tank

10. Squeeze coolant pipes again

11. Just before coolant begins to boil over replace cap (Warning! Coolant will now be in excess of 100*c)

12. Turn off ignition

13. Release pressure in expansion tank (again with caution)

14. Give the coolant pipes another good squeeze just to be sure (these will also be bloody hot)

15. Top up if required!

 

Also if your mix of coolant to water is correct you should now have almost exactly the right amount of coolant left in the G12+ bottle to mix with water and carry with you just in case!

 

I've done this twice now and haven't had any issues at all!

[cvw 0]

where would we be without nocrap. chers buddy

[nocrap 0]

No worries matey , just happy to be of help

[cvw 0]

ok so followed it the way nocrap said and everything went ok top banana . i was changing the tank because i was under the impression that the sensor inside had gone as the temperature warning light kept flashing as it does when theres not enough water in. but this light is still flashing what else could it be folks?

[nocrap 0]

nothing else...just that sensor being knackered

[VEEDUBBED 0]

Also worth mentioning that when you open the expansion cap be carefull that the inner o-ring isn't displaced or turned inside out,check carefully and replace if it looks damaged.

1 other thing that happened years back on my golf T.16v when the headgasket went,DON'T attempt to open the expansion bottle because the pressure created within the cooling system will force off the o-ring and no amount off tightening of the cap will seal it again untill all the remaining coolant's has all been blasted out,possibly over you...

[nocrap 0]

I just use the shaken up cola bottle theory......open turn slightly until some pressure is released, then close then open slightly again. repeat until all pressure is released.

[Supercharged 2]

ok so followed it the way nocrap said and everything went ok top banana . i was changing the tank because i was under the impression that the sensor inside had gone as the temperature warning light kept flashing as it does when theres not enough water in. but this light is still flashing what else could it be folks?

 

Try bridging the plug to test,

 

Was it a genuine tank? the pattern ones are useless...

 

If not the tank then you need to look at the fusebox to check nothing has fallen out.