cooling system

hi whats the best way to get air out of the cooling system 300 tdi L reg thanks Neil.

all i have ever done is undo the bleeder bolts and fill untill water comes out of them, close them up and should be fine. also have the heater on hot.

remove stat housing bung and rad bung.
fill from expansion cap untill water comes out of rad bung.
replace rad bung and expansion cap. (this puts level about half way in header tank)
stick a suitable funnel into stat housing bung and fill with water. (let water sit in funnel)
squeeze rad pipes repeatedly untill all air bubbles come out of system.
remove funnel and replace stat bung
doesent matter where heater control is, as heater matrix runs constant.
(cold air diverted by baffles)

hi sage,
i've recently changed my thermostat housing on my disco 300tdi L reg,as a previous owner bodged the bleed cap,
knackered all the thread and no matter what or how i tried i couldn't stop it leaking.
after changing the housing, i replaced the thermostat with a new one,
i toped up through the bleed screw hole untill water level came up,
screwed the replacement copper cap and rubber seal.
started the disco and ran up to temp,
once at temp opened the bleed screw, some air came out and ran with water,
now heater nice and warm constantly, temp ok, and had no problems since.
hope this helps

hi ive now done that thanks but is it normal to have a small hissing noise comeing out of the expansion tank cap?

sage said:

hi ive now done that thanks but is it normal to have a small hissing noise comeing out of the expansion tank cap?

Click to expand...

when the caps on or when you undo it?

shouldnt be any hissing unless you've boiled it