Bleed screw

[warge]

Hi there...quick question. I'm trying to bleed the coolant system on my 2.1 petrol 1989 van but I'm not getting any coolant coming out of the bleed valve on the thermostat housing when I open it out...thing is...is this screw/valve supposed to come all the way out ?...mine turns about 3 anti clockwise turns and then i meet resistance and I don't want to force it as i'm worried it will break. Should I be able to remove the screw completely or does it only go so far ?
Many thanks..warge

[Aidan]

doesn't have to come out completely once it's loose it lets coolant pass
I have a customers van where the threaded insert the screw is in rotates in the plastc so doesn't loosen at all, will require a replacement radiator for that one

[warge]

Thanks for the reply...as nothing is coming out when screw is loose will it be best to replace thermo housing and do they come with new bleed valve fitted....cheers..warge

[Mickyfin]

Afaik, the bleed screw in the thermostat housing simply assist removing trapped air in the cooling system. I not so recently bled my cooling system as per Simon Baxters instructions on The Brickyard, bleeding from the rad bleed screw, and undoing the bleed screw on the thermos housing really did help, as I noticed a load of bubbles coming out the rad bleed screw when undone a few turns.

Once no more bubbles, tighten said thermo bleed screw, and continue to bleed through rad bleed screw, following Simons instruction on moving vehicle front to higher ground, and you will be fine. Worked for me.

[marcus_asparagus]

Warge,

You are correct in that bleed screw only turns a couple of times - do not force it anymore or off it comes!
It allows air to vent through the top coolant line around the engine bay to the header tank, you'd be lucky to see anything happening, but it does.

You will not need to replace that thermo top as the screw does not come out, in fact you are lucky it moves at all as most are solid!

Good luck with the rest of the bleeding process.

Mark.