16
Now it’s time to move onto the
expansion tank. Since our previous
radiator did not use an expansion tank
we had removed the mounting straps
and bracket. We got a new bracket (PN
M-235A) from Zip Corvette and attached
it to the inner fender using new bolts.19
Another cheap and easy step for a
cooling system overhaul is install-
ing new heater hoses. You can buy the
hose in bulk at the local parts store or
you can buy the correct stamped hoses
from any Corvette parts supplier. We
opted for the parts store hoses and
installed them with new clamps.23
We spun the fitting until it was fac-
ing the front of the car and then
trimmed the heater hose for a nice fit.
Next, we trimmed and installed the lower
heater hose.17
Next are the expansion tank straps
(PN M-235). The straps are not pre-
bent so we did some trial and error fit-
ment to get an idea of the correct shape.
After getting them dialed in, we attached
the lower portion of the straps to the
bracket.20
Another piece from the Zip Cor-
vette catalog is this heater hose
T-fitting (PN M-207). It connects the
upper heater core hose to the expan-
sion tank and allows free coolant flow
from the water pump.24
Finally, we installed 3/8-inch hose
from the expansion tank to the
radiator, as well as a 3/8-inch overflow
hose.18
The new DeWitts expansion tank
(PN 421) is an exact reproduction
of the original Harrison tank. We still had
to do some final tweaking on the straps,
and then installed the new strap bolts
from Zip.22
Although
it is
rather bulky,
this 90-degree
fitting is a
much bet-
ter piece than
some of the
chrome-plated aftermarket versions. We
removed the valve cover to give us a little
more room to tighten the fitting.21
One
last trip
to the parts
store yielded
us some new
heater hose fit-
tings for the
water pump
and the intake manifold. We coated the
threads with pipe sealant before thread-
ing them into place.25
With a combination of parts from
DeWitts, J&D Corvette and Zip
Corvette, we completely overhauled
this Corvette’s cooling system and gave
it a super clean look. The final step was
pouring a fresh mixture of coolant and
water into the expansion tank and tak-
ing it for a spin ... and 180 degrees never
looked so good!