Fixing Door Leaks on C3

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by: Larry Ingram

those of you
without water leaks I hope that you know how lucky you
or please allow me to congratulate you on your ability to cure
them. I have been working on Corvettes for 20 years and although I don�t
do water leaks all that often it seems that I have finally
found one
of the worst…the door leak.

found the source of this particular water
leak when I ran a trickle
of water around the edge of the
windshield at the area where the door
weatherstrip meets the
pillar post weatherstrips. The reason I even
found the leak
was that I had the door upholstery off for other reasons
this allowed me to see the unexpected. Because of the angle of the
inner door shell (it slopes outward from top to bottom) the water both
runs down and splashes out from inside to the upholstery
side of the
door, then ends up on the sill plate. For
1968-77 cars the water is
then seen as a puddle on the metal
trim. On 1978-82 cars it is absorbed
by the carpet on the
sill, without the telltale evidence.

factory must have known this and they fully
prevented it by applying
a moulded sheet of plastic to the
door shell before installing the upholstery.
On all other
types of cars the water shield is usually taped in place
a few areas so that it doesn�t fall off while applying the upholstery
and the lower part of the shield gets tucked into a slot along the door
shells bottom, redirecting the errant water back into the
door allowing
it to drain as designed. This is where SHARKS
are unique. There is no
slot. The factory applied a type of
caulking or sealant around the entire
perimeter forcing any
water to be redirected back inside the door and
subsequently drained at some very specific holes. Over time, the
doors usually require service of one kind or another and this sealing
material gets separated, or possibly lost. Unfortunately, unless the
shield is resealed along the sides and bottom then you now have a new
water leak.

is likely that the
factory applied sealer could be reused when the car
reasonably new but after this many years press and smudge as you
want I don�t think you can fully expect to rejoin the shield to the
door using the disturbed original sealant.

leak that also goes hand in hand with
the door design is the access
hatch cover used to remove the
window regulator from the door. This
hatch must also be
sealed to the door along its bottom for sure and
around its perimeter. Reinstall all the screws to keep it
that way If your car has lost most of the screws or the holes are worn
(oversized), don�t despair; simply use larger diameter
screws and if
necessary enlarge the holes on the hatch

you suspect that
you have either or both of these leaks then the fix
is to
remove the door upholstery and ensure that the water shield and
the access hatch are even still there. Many are not, for obvious
know; the factory put it there but a previous
mechanic decided it wasn�t
necessary and threw it away. If
the hatch is missing try to get one,
but you could seal this
area with duct tape or plastic just as you will
the entire
door. If the water shield is missing or badly damaged use
sheet plastic and cut it to fit the area covered by the upholstery.
NOTE: the front doesn�t follow the door shape as it does along the bottom
and rear edges. Cut only the holes necessary for the door
handle and
any wiring or mirror controls. To apply the
shield to the door use a
latex based caulking or silicone,
although this latter material may
not work as well over the
long haul. The important thing to bear in
mind here is that
a sealant with a strong offensive odour will pollute
interior cabin with it�s smell. Apply a bead about 1/4\” in diameter
around the perimeter and about �\” in from the edge, place the shield
onto the door and press into the sealant squashing it to
about 1/4 its
original thickness. Make sure that you push
the shield onto the sealant
along the entire bottom edge
especially and that there are no areas
not glued by the
caulking, after all any gap be it ever so small along
bottom or lower sides is really just a drain and is not desired.
The reason you did this repair is solely to ensure that the water is
always redirected back into the door at the bottom edge so it can then
drain out the designed way. Anything else was just practice
and you
will be back again soon.

While you are in the door please lubricate
everything you see; the latch
mechanism, tracks, and the
window regulator seldom get greased or oiled
so if the door
is apart anyway now is the time to prevent a problem
An ideal product for this is a can of spray white grease that
has a plastic type of straw but engine oil from a squirt can or paint
brush is still a great cure for dry moving parts. Most of all use this
rule: if \”General Motors\” paid someone to design it,
someone to manufacture
it, and someone to install it then it
IS NEEDED. No successful company
spends money doing that
just to increase costs which ultimately raises
the selling
price of their products.


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