Pontiac Fiero 1988 Service Manual page 362

ENGINE COOLING 6B-13
8. Withdraw the torch and rub the adhesive stick
on the repair area (Figure 21). The adhesive will
flow at a temperature of approximately 500°F
(260°C). If the stick doesn't start to melt,
remove it and reapply the heat. Do not heat the
stick directly with a flame* High heat will
burn and char the adhesive.
Figure 21 Applying Hot Melt Adhesive
9. Continue heating until the adhesive flows and
wets the entire repair area and fills the joint. If a
hole is in the center of a tube, heat the tube and
let the hot surface melt and pull in the adhesive.
The force of the flame or heat gun will also tend
to guide the adhesive toward the hole. For leaks
between a tube and header, flow the adhesive
completely around the tube and header joint
with the tank installed.
10. Heat the repair area until the adhesive is bubble-
free and smooth, with a light yellow color. Cur-
ing is not required.
11. Test the radiator for leaks, when cool. If the
repair area still leaks, reheat it gently to dry it.
Heat and reflow the adhesive, or apply more as
necessary, to repair the leak.
TANK GASKET LEAK REPAIR
Tank gasket leaks can easily be mistaken for
tank or header leaks. If a plastic tank leaks from the
header joint gasket, tighten the clinch tabs with lock-
ing-type pliers (Figure 22). If this method doesn't seal
the leak, remove the tank for further inspection.
1. Pry open the clinch tabs, except those under
inlet, outlet, and filler necks, using J 33419-1 or
a screwdriver (Figure 23). Lift the tabs only
enough to allow removal.
NOTICE:
Care should be taken not to overbend
tabs. Overbending could result in breakage. If
there are more than 3 tabs broken on one side of
the header, or more than 2 adjacent tabs together,
the core must be replaced.
2. Lift the tank and slide it out from under the
remaining clinched tab. You may have to tap
the tank with your hand to dislodge the gasket.
Lift the remaining tab(s) with pliers.
H20014-6B
Figure 22 lightening Clinch Tabs
H20015-6B
Figure 23 Opening Clinch Tabs
3. Remove and discard the gasket.
4. Clean the header and gasket groove of all dirt
and old rubber.
5. Clean the sealing edge of the plastic tank.
6. Examine the header gasket surface and tank
flange for evidence of leakage, and clean or
repair the surface to remove dirt, burrs, and
bumps.
7. Remove the oil cooler, if equipped, and install it
in the new tank.
8. Dip or coat the new tank gasket in engine cool-
ant and position it on the header surface. The
coolant helps hold the gasket in place.
9. Position the tank and gasket to the header,
clamp it in place and secure it by bending four
clinch tabs as shown in Figure 24.