Re: Tom has a gas leak and it isn't Wanda's cooking

["Bill Thebert" <bthebert@domain.elided>]

> The water level was fairly full when I pulled the cold rad cap off.  I
> started the truck up, and let it run for a while... after a bit, I assume
> the thermostat opened (kept checking the temp gauge) and then the
antifreeze
> started to run over the top of the open radiator.. 

Tom:

I believe it's quite normal for the coolant to expand as it warms and to
overflow out the top of an open radiator.  This is certainly not the same
as something forcing excessive coolant out the overflow tube -- against the
pressure of a sealed radiator cap.  I don't believe that this overflow is a
"sure sign" of a blown head gasket.

> NAPA should have new head gaskets for me by Wednesday or so.. $50 for the
> pair.  How much of a chore is it to yank the heads and swap the gaskets?
> Anything I should know about?  Can I do this w/o removing the intake? 
What
> *else* should I do "while I'm in there"?

I'm not up to speed on your entire thread here . . . 

IF you determine that the head gaskets need replacing, it can be done in a
single evening.  I replaced both sides in a borrowed garage in Springfield
a couple of summers ago.  Started about 6PM, finished about midnight.  No
air tools, unfamiliar surroundings . . .

Step 1: disconnect & remove the battery.

Step 2: Verify that you've disconnected & removed the battery <g>

All accessory brackets come off & get laid aside (PS pump, alternator, AC
compressor, etc.

Liberate the intake manifold:
-----------------------------------------
Disconnect all attachments of the top-side engine electrical harness
(ignition, temp, charging, etc.).  Disconnect throttle linkage, vacuum to
brake booster, etc.  Disconnect upper radiator hose, heater hoses, bypass
hose, etc.  Label all spark plug wires at the plug ends.  Disconnect from
the plugs but leave them on the distributor.  Bundle them & tie them out of
the way.  Disconnect the coil-to-distributor wire. Disconnect fuel supply
to the carb.

I removed the intake manifold with the TBI/carb still attached.  If you're
careful, I think you can get the manifold off without disturbing the
distributor.

Liberate the heads:
------------------------------
Remove valve covers, rocker assemblies, and push rods.  Remove exhaust
manifolds (or headers) from the heads & push aside.

You're now ready to unbolt the heads & lift the buggers off.  Be careful;
they're darn heavy.

> And of course... *is it* the headgaskets?  How do I go about narrowing it
> down to the head gaskets?  I do believe I have the tools to do a
compression
> check, though I've never performed such a check before.

If a defective head gasket is allowing hot combustion gases into the
coolant, you will surely overheat as well as blow a few bubbles.

If you think you're sucking coolant *into* the cylinders (causing your
"smoke"), there will almost certainly be a distinctive ethylene-glycol
aroma to the exhaust.

You mention that you've purchased the head gaskets -- but you need almost
an entire "top end" kit.  You'll need valve cover gaskets, plus intake &
exhaust manifold gaskets at a minimum.  If you have any leakage around your
valley pan, now's the time to correct it while the intake is off.

Good luck,

Bill Thebert