We did the 'block test' I think it's called, repeatedly checking for
exhaust gas in the coolant, but never detected any. But yes,
definitely air getting in, expanding and blowing out the coolant. Why
wouldn't the reservoir cap bleed out the air? Is it possible that
somehow, a leak could somehow be one way. That it would not leak out,
but under some scenario, angle of vehicle while engine braking, for
example, it would pull air in.....?
Miguel

On Tue, Aug 25, 2009 at 9:27 AM, Matthew Snook<matt@snooksband.com> wrote:
> Miguel:
>
> Your comment about the heater going cold before the engine overheats sounds
> to me like there is air in the system.  That has happened to me before.  A
> leak may be losing coolant, or somehow air is getting into your system.
>
> Matt
>
>
> -----Original Message-----
> From: miguel pacheco
> Subject: Re: rear heater ETC
>
> ...With the heater running, I know it's about to overheat when the blowing
> heat suddenly becomes cold...
>
>