Re: bleeding air from cooling system

["Dean W. Cains" <dwc@domain.elided>]

Hi Brian and Group:

I've never understood how the "trick" of squeezing the upper radiator hose 
will accomplish anything, with regards to creating negative pressure in the 
cooling system.  I know the method involves removing the cap, squeezing the 
top hose, and replacing the cap before releasing the hose.  But, on all my 
cars the radiator cap has a little one-way valve that would just let air 
bleed back into the system, equalizing any pressure differential.  The 
valve is there to suck coolant from the reservoir into the radiator, as it 
cools, to replenish a low fluid level.  The valve would also prevent hoses 
from collapsing as the system cools, with or without a coolant 
reservoir.  My XKE had a radiator cap that was just a cap, without any 
springs or valves, but the metal coolant reservoir tank had a conventional 
pressure cap.

Regards,

Dean W. Cains
Lutz, FL
'74 Spider Veloce

At 03:22 PM 7/8/2002, you wrote:

> Date: Mon, 8 Jul 2002 11:44:50 -0400
> From: "Brian Shorey" <bshorey@domain.elided>
> Subject: RE: bleeding air from cooling system
>
> > Would someone refresh my memory on the method I've seen
> > mentioned here about bleeding the air from the cooling system
> > by squeezing a radiator hose?  I don't remember the
> > particulars and I can't seem to get Google search on the Alfa
> > digest website to work with my computer.  A direct response
> > would be great as I'm about a week behind on my digest reading.  TIA.
>
> Squeezing the hose is a trick to get some negative pressure into the
> system so coolant won't leak while retorquing head bolts (trick courtesy
> of Father Fred, IIRC).
>
> I've never heard of it being used to bleed the system.  The bleed nut is
> about as high in the system as you can get, have you tried that?
>
> bs
--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided