Air lock

[Tony5496]

Hi I am a new member I don't know if I am in the right place to post this maybe someone can tell me where to post this as not very good at all this .the problem I've got is that I've had the cambelt and water pump done at the same time and I've got the problem of very high presure in the expansion bottel even when the car is cold .I undo the lid and it fills the bottel and over spills the coolant so can't get a proper level in the bottel .so I do it back up and drive it and it forces the coolant to below min mark only had this problem since work done usually when cold it would let a littel pressure out and top up if needed but not over spills like it is.could a air lock cause this any help would be a great help the car is a mk2 1.9TDI on 2001

[Mirez]

Hi Tony and welcome along - your posts in the perfect place so no worries

Where did you get the work done? I'd be inclined to take it back and let them sort it our to be honest as if it was working before then it's something they have done. When refilling the Galaxy you have to do it slowly to allow the air from the rear heater matrix to escape, a lot of garages will do it quickly as time is money.

[Tony5496]

Hi thanks for reply I do remember when I got the car back I checked it the following morning and checked the expansion bottle and it was empty so I put about three litres in it and did not know it was meant to be put in slow! And I have lost the rear heater it is only blowing cold air out now but it was nice and hot before this all happened just wondering would a big air lock cause the rear heater to blow cold now and if so what can I do

[Mirez]

Yes, you need coolant for it to get hot! If its filled with air then you'll get nothing back there.

My advice would be to split and drain the system and then refill slowly. Whilst you have the system empty it's always a good idea to use a hose to flush the system of any debris that's built up.

[Tony5496]

Hi yes what's the best way to empty the system and where do you put the hose in to flush the system out ? And when refilling do I just refill in the expansion bottel and fill it very slow or do I need to do anything else don't suppose you know how many liters it holds many thanks for all your help and what a great forum this is 

[Mirez]

On some there is a drain built into the radiator, others I just disconnect the lower hose as it enters the radiator. You then put the hose into both, now separated, ends. If your system has never been flushed then a better place to separate is at the aux heater or the aux pump so you can wash out the entire system.

Most importantly, you never flush a system with a hose if the engines been running. You want the car stone cold and not warm so there is no thermal stress from icy cold water!

I vaguely recall the system being about 8 or 9 litres but either way a 5 litre bottle pre-diluted is ample.

[Tony5496]

Ok thanks very much is the aux heater the two pipes at the top on the back of the bolk head the ones that I think run into the heater sorry for me asking so many questions as I only know the basics lol

[SilverBeast]

Auxiliary Heater is under the floor of the car (exposed to the weather) in front of the nearside rear wheel.  It has a small exhaust on it see here -->https://www.fordmpv.com/smf2/ford-galaxy-reference-library/galaxy-mk2-auxiliary-booster-heater-guide/