Coolant bleeding

[Thom.milburn]

Hi guys,

quick one - is there a method for filling a t6 coolant system from empty? I changed my EGR today but upon replacing the coolant it barely took 1litre although I dumped a few when I started.

I presume get engine warm, thermostat will open allowing coolant to fill block and I’ll top up from there? On my old T4 there used to be a bleed valve at the top of the system but I can’t find anything obvious.

 

[Niknak]

If I was you I’d pop out now and brim the bottle and leave over night they normally self bled easily, although I do use a vacuum filler myself

 

[Loz]

The workshop manual mentions using a vacuum system and the use of the vw vas diagnostics with a procedure that must run the various cooling pumps. From empty the system takes 8 litres.

 

[Dellmassive]

If I was you I’d pop out now and brim the bottle and leave over night they normally self bled easily, although I do use a vacuum filler myself

Got a picture or link to one of those?

Are we talking about the large filling funel with the one way valve at the bottom?

 

[Niknak]

No it’s air operated connects to coolant filler use compressed air to vacuum the system then open a valve on a reservioir container and it fills that way

 

[Dellmassive]

gotcha, just found them . . . .

it runs off shop Air.


I've got a coolant pressure tester . . . . suppose this is the opposite =]


Looks like a nice gadget to add to my collection . . . . shame i haven't got an Air Compressor . . . . Yet !

Vacuum Purge Tool, Automotive Universal Radiator Pressure Tester Cooling System Tool Set Vacuum Purge Coolant Refill Kit with Carrying Case : Amazon.co.uk: Automotive

Buy Vacuum Purge Tool, Automotive Universal Radiator Pressure Tester Cooling System Tool Set Vacuum Purge Coolant Refill Kit with Carrying Case at Amazon UK. Free delivery on eligible orders.

amzn.to

 

[Dellmassive]

This is what i was thinking of . . . . .

I see some USA YT Mechanics use them a lot (South Main Auto, Eric The Car Guy etc etc)

EPAUTO Spill Proof Radiator Coolant Filling Funnel Kit : Amazon.co.uk: Automotive

EPAUTO Spill Proof Radiator Coolant Filling Funnel Kit : Amazon.co.uk: Automotive

amzn.to

.

 

[Niknak]

Yes that’s the type

 

[Niknak]

Not the funnel one that’s for partially sighted techs

 

[Thom.milburn]

Thanks for the advice guys. The reservoir is full so hopefully it’ll encourage it to burp during the night. I’ve not got a vacuum tool so may have to look into alternative methods!

for reference to drain the system I simply removed the coolant sensor below the rad and certainly didn’t get a full 8 litres out so hopefully there is a fair bit still in the system which can be circulated and further encourage bleeding.

Are there any ‘manual’/tool less methods I can employ to ensure proper bleeding, I worry about hot spots and such!

 

[Dellmassive]

The cooling water circut looked super complicated last time I looked at it in the OEM Book.

You would need VCDS or other similar Pro Scan tool to drive the circulation pumps and valves.... I don't even think the Autel 908 will do it.

Like @Loz said VW diag kit will run a sequence of engine, pumps, valves in sequence to purge the system.

So VCDS or the Vacume method @Niknak mentioned.

Failing that it will have yo be old-school.


Fill to the brim on a cold engine,

Run engine till warm to open thermostats,

Give it a few blips of the throttle to encourage the water pump to push out air.

Get the cap on before the temp gets to high or the coolant may start to boil up and you will have to start over.



Wait till its cool, check, test, repeat.

 

[DXX]

Carry some coolant with you for a few days in case you need a top up.

 

[DXX]

@Thom.milburn did the coolant bleed through ok without assistance?

 

[Thom.milburn]

@Thom.milburn did the coolant bleed through ok without assistance?

it did - yes! Idrained the coolant via the lowest point temp sensor beneath rad (the one in the hose) and then brimmed the coolant bottle and blew into it hard I did this several times and then just topped up after a couple of short but warm journeys

 

[Klemzy]

hi can you please help me with my problem... I have T6 150hp dsg 2016 caravelle and i have problems with coolant disappearing but dont know where... My mechanic checked all the sistem and top up the coolant (run a sequence) and after 2000km my coolant light on. When I open the coolant cap there is a lot of presure (even when the engine is cold) and liquid comes back to the TOP mark.
Is the problem in cap or in expansion tank?

 

[Niknak]

Sounds like you could have a egr cooler gone my advice would be to drain the coolant out and smoke test the system and remove the egr pipe to check for smoke

 

[Loz]

Not really surprising its hard to bleed

 

[itsmedee96]

If I was you I’d pop out now and brim the bottle and leave over night they normally self bled easily, although I do use a vacuum filler myself

when you say brim the bottle do you mean fill
it to max? or to top of bottle

 

[Niknak]

From a drained down system fill it as much as possible and keep doing so until it’s stable, if your not used to a manual fill and bled process I suggest you leave it tbh you don’t want air pockets, as you do need to run the vehicle and keep an eye on he level

 

[itsmedee96]

From a drained down system fill it as much as possible and keep doing so until it’s stable, if your not used to a manual fill and bled process I suggest you leave it tbh you don’t want air pockets, as you do need to run the vehicle and keep an eye on he level

iv changed my coolant bottle yesterday and running it round today the coolant light came on so just topped it back up