cant get rid of airlock after fitting new t/stat and rad! its not head gasket/s had that checked! the right/best way to do this would be very much appreciated. cheers..

 

Best way:

let it cool down and make sure you've got the heater on full heat, remove header tank cap and top up if needed (that's why you need it cool) then start it up, any air will be expelled through the headers tank and just keep topping it up till it starts to expand with getting hot, this should remove any air locks.


Jim

 

i wish it were that simple! cheers..

 

Take it that's how you did it before then? What symptoms make you think you have an air lock?

 

A sure way of ensureing a system is full is to remove the upper hose between the engine block and the rad. Take yourself a flexable funnel and feed into engine port. Pour coolent in until theres a steady flow out the top. Do the same on the rad port until a steady flow appears. Do this real slow and your get no problems with air locks. Reconnect hose. Replensh header tank untill the fluid level holds its own. Once its done than you can start the engine. Leave the header cap off for a moment. Replenish header tank as required until once again fluid level holds it's own. You may need to tease the lwr hose a bit to expel any air that may be in there. Replace header cap. Bring system to temp and pressure. Chk for leaks.

Over the next few days replenish system as required. Heater controls to full when servicing system.

Flexable funnel............plastic drinks bottle with 12" hose.

7.5 ltrs turbo engine. Although you'll only get approx 4.5/5 lts back in.

 

I found just squeezing the main hoses while refilling very slowly worked, took me about 10-15mins but I got the same amount back in as what I took out.

 

Very very slowly via the header cap/tank on the LH side of the engine is the best way.

 

cheers for all replies! will try again as soon as it stops raining..

 

Just what i did last week

 

Personnally i wouldn't service a cooling system via the header tank. Just take a look at those small hoses that the fluid has to get through first. Although i haven't done it this way i would think it would take an absolute age to fill system via header tank also i'm not so sure that all the fluid really gets into the system doing it this way.
I have heard a few horror stories where people think they have filled a system to full only to find they have a seized engine shortly after wards.
Remove the hose between rad and engine block you can be sure to fill the system to full and in reasonable quick as well. Although i will say a little care is still needed and that last minute top up at the header is still required.

 

The system fills quite quickly via the header tank, and the two turbo return hose acts as the air return when filling so all the air gets pushed out, having changed the coolant several times on my old engine, and recently on my new build this way I have never had an airlock using the procedure I posted further up.