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Subject:Re: 91 GL running hot all of the sudden
From:SStones
Date:Tue, 26 Aug 2003 08:43:52 -0400

At 07:18 PM 8/25/03 -0400, John wrote:
>Dan,
>Get a little pump siphon and take the excess out of the overflow tank. That
>way you're right there to see when the proper level is reached.

Dan wrote:
>      although now I
>      need to drain out the excess.

If you take the cap off of the overflow tank, the liquid above the bottom
of the cap will flow out.  The max-line is pretty much at the bottom of the
cap.
If you want to drain the overflow tank more, just take the hose off of the
expansion tank cap and hold it below the bottom of the overflow tank,
gravity will do the work for you.

A pint of straight water into expansion tank mixing with the nearly 50/50
coolant mixture won't make a noticeable difference to the overall
mixture.  Just remember to add coolant next time you add anything.

With regards to the overheating problem, though...
Feel the radiator with your hand, down in the bottom left (your right when
face to face with the van) corner near the thermo switch. If it's not hot
enough down there to make you want to pull your hand away, you have a flow
problem. Clogged radiator? Dead in the closed position thermostat?(Rare but
possible) Dying water-pump?(If the heaters are blowing hot enough to cook
your toes, and the pump isn't screaming, it is probably good).
If the radiator is hot, but the fan still isn't coming on, pull the
connector off the switch. Check that the Red w/ white wire is +12VDC.  If
it isn't, check back to the fuse (number 7 in my 1985)...
If the Red w/ white is hot, Jumper it to Red w/ black.  The fan should come
on low.  Now jumper it to Red w/ blue (while leaving the other jumper, all
three jumped together) Now you should have the fan going fast enough to get
the van moving if the parking brake wasn't on.  Now you know that all the
wiring works, blame the thermo switch and replace it if the jumper tests
worked and you can feel that that corner of the radiator is so damn hot
that it is obvious that the fan needs to come on.