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Discussion Starter #1
Hi everyone, hope you're all okay and healthy during this lock down..

I am just putting this up here for some guidance on a Coolant Change and flush..

I've got a 1998 T4 Caravelle LWB 2.5 TDI (ACV Engine)
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I've done plenty of coolant changes/flushes before on my other cars in the past but this will be the first time on my T4.. Just wondered if there were any tricks or anything that someone would recommend?


I would:

1. Remove header tank cap
2. Remove bottom hose of radiator
3. Let coolant drain out
4. Run a hose through the radiator and the header tank until the water runs clear
5. Reconnect all of the hoses
6. Refill with fresh G12 Coolant
7. Run the van up to temperature with the header tank off, heaters on full and squeeze pipes to expel air
8. Once confident, screw header tank cap back on
9. Job done.

I'm just wondering if that's all correct? I know some folk add an initial fill-up on deionised water between 3./5. and then run up to temperature/drop out again which I may do after an inspection.

I was more wondering if the method of 'burping' the system was correct as obviously I want to avoid airlocks!
Also, does anyone know the capacity of Coolant this Van takes?


Any help is much appreciated,
Thanks very much!

Lee
 

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There's an official drain hole on the corner of the metal coolant pipe running from the gearbox side. If you don't use that you may find the engine core will not empty fully. On filling there is a bleed screw on the pipes running up to the heater matrix to help avoid airlocks when filling. I also undo the thermostat to make sure the core empties.
Coolant amount will be listed on a google search pal, I can't remember off hand.
 

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Ensure the heater valve is set to "open" to ensure you flush the matrix and pipes out when you drain it.
If you have a rear heater (or 2!), ensure that is open as well.
 

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Discussion Starter #4
There's an official drain hole on the corner of the metal coolant pipe running from the gearbox side. If you don't use that you may find the engine core will not empty fully. On filling there is a bleed screw on the pipes running up to the heater matrix to help avoid airlocks when filling. I also undo the thermostat to make sure the core empties.
Coolant amount will be listed on a google search pal, I can't remember off hand.
Hi BingleyLion, thanks a lot for your advice there - I did find the coolant drain screw on the metal pipe after you mentioned it. But it looked pretty corroded and rusted on. So I decided to leave this at the moment until I have a definite replacement screw and washer for it.. Didn't want to leave myself with a snapped drain screw in the pipe!

I've now done a complete coolant flush and change, changed some hoses, the thermostat housing and thermostat.. Figured I may as well considering it was up on ramps anyway and it saves me doing it at a later date.. The van got up to temperature and now the fans blow red hot constantly.. There must have been a small issue with the old thermostat, it looked like the original one so it's definitely proved its mileage. All good now and the van is better than ever!

Thanks again for all your help, really appreciated!
 

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Discussion Starter #5
Ensure the heater valve is set to "open" to ensure you flush the matrix and pipes out when you drain it.
If you have a rear heater (or 2!), ensure that is open as well.
Thanks a lot for your advice there Or_GazM - I've now done a complete coolant flush and change and made sure all my fans were blowing hot as the van got up to temperature.. Now they're blowing red hot constantly, much better than they ever were! All good now and the van is better than ever and ready for the winter snow up here in Scotland.

Thanks again for all your help, really appreciated!
 
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