[MR2] MK1 Coolant Problem

[Donald Chalfant]

my guess.   . No Vacuum when cool
----- Original Message ----- 
From: "Aaron Willis" <te51levin at fastmail.fm>
To: "Dennis McFayden" <mr2garage at yahoo.com>; "MR2 Email" <mr2 at mr2.com>
Sent: Sunday, September 20, 2009 12:00 AM
Subject: Re: [MR2] MK1 Coolant Problem


> Have you ever replaced the overflow cap and its hoses?  They tend to get
> brittle and leak, if not come apart entirely.
>
> On Sat, 19 Sep 2009 20:54:10 -0700 (PDT), "Dennis McFayden"
> <mr2garage at yahoo.com> said:
> > I posted this problem before and got a couple of good ideas but not
> > worked. The problem is that my cooling system does not suck back the
> > coolant from the overflow tank.
> >
> > I have replaced the radiator cap three times with new OEM caps. N o help
> > there. The symptoms are:
> >
> > 1) I have pressurized the system to 16 PSI for over an hour and the
> > pressure holds, no leaks. I pressurized the whole system even the
> > drop-down tube going into the overflow tank.
> >
> > 2) I have not lost any coolant.
> >
> > 3) With my pressure tester attached in place of the radiator cap I can
> > create a vacuum to draw the coolant back into the system.
> >
> > The only thing I can come up with now is a possible flaw in the seal
> > between the cap and the place where it attaches. No flaw is visible. My
> > pressure tester attaches in the same way as the radiator cap.
> >
> > It may be possible(?) that air gets sucked into the cooling system
> > instead of the coolant from the over-flow tank. That would be a rather
> > complex one way leak that would not show up under pressure. I have also
> > created a vacuum in the system to see if it would hold. It did but I
> > didn't create much of a vacuum.
> >
> > Any ideas would be appreciated. The car cooling system doesn't come
close
> > to over heating, works very well even the the AC on and our high CA
> > temps.
> >
> > Dennis
> >
> > This is a '87 MR2
>
> -- 
> Aaron Willis - '85 AW11 7A-GE, MSnS-Extra, E85, etc
> Club discount on OEM Toyota parts - email me at work! awillis at lithia.com
>
>
>
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