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Re: Pressure caps on 1600

To: robbpynes <robbpynes@continet.com>
Subject: Re: Pressure caps on 1600
From: John F Sandhoff <sandhoff@csus.edu>
Date: Wed, 24 Mar 2004 21:53:25 -0800 (PST)
> Have a buddy that has a 66 1600 that the temperature rises to 250 when
> he drove it last weekend.

Is he sure this temp is accurate? The electrical gauge may be
telling mistruths.

> That guy told him they are a bitch to fill with water...

Maybe if you forget to take the cap off first :-)
Never had a problem filling mine. NOTE: many aftermarket thermostats
do not have the 'jiggle valve' that allows air to escape during filling.
You can drill a SMALL hole (1/8-3/32) in the flange to create a slight
leak.

> I was wondering if maybe he has worn out pressure caps on his system.

Only ONE pressure cap should be on the system.
The thermostat tower on the head gets sealed with a solid cap.
Still available from the dealer, but more $ than you'd think.

The pressure cap goes on the overflow tank, which should be
half-filled with coolant when the engine is cool (the engine/
radiator should be totally full). Original had a pushbutton
pressure release and was 7 PSI.

Let me repeat: 7 PSI.

> ...when others that I am running with are pulling over to cool off
> or add water as they are overheating.

They're overheating for some reason other than the pressure cap.
Ignition timing, clogged water passages, stuck thermostat, leaky
head gasket, bad radiator, lean fuel mix. Check 'em all.

-- John
    John F Sandhoff   sandhoff@csus.edu   Sacramento, CA






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