Pontiac Fiero 1988 Service Manual page 359

6B-10 ENGINE COOLING
1. Remove dirt and insects from the fins with a
common water hose without a nozzle. Excessive
water pressure could damage the fins.
2. Scrub the core with a soft-bristle brush using
clean, hot water, or hot water with a mild deter-
gent solution.
On-Vehicle Pressure Testing
You can pressure-test the aluminum-plastic
radiator with a common pump and gage, such as BT-
7002-3 or J 24460-01 with J 23699 (Figure 10). With
the system at a cool temperature, remove the radiator
cap, connect the gage, and apply normal system oper-
ating pressure. Do not exceed 20 psi (138 kPa).
Watch the gage needle for an indication of a leak, and
examine the radiator and other cooling system parts
for signs of escaping coolant.
Repair all hose and hose connections as
required. Also check radiator cap to ensure that it will
maintain the correct pressure.
If the radiator is found to be leaking during the
pressure test, mark the leak area so that it is easily
found once the radiator has been removed from the
vehicle.
Figure 10 Pressure Testing Radiator
Off-Vehicle Leak Testing
N O T I C E :
Do not use boil-out tanks, or vats, or
other tanks that have been used for copper and
brass radiators. The flux, acid, and caustic
cleaners remaining in these tanks will attack the
aluminum and cause radiator failure. A separate
test tank containing clean water is strongly rec-
ommended for servicing aluminum-plastic
radiator.
1. Install test fittings or rubber test caps in the inlet
and outlet necks and seal the oil cooler fittings
with metal plugs to protect the cooler and keep
the fluid from running out (Figure 11).
2. Attach pressure tester and gradually apply air
pressure until 20 psi (138 kPa) is attained. Do
not exceed 20 psi (138 kPa). Check pressure
gage to see if there is a pressure loss. To ensure
that there are no small leaks, run water over the
repair area and look for bubbles. (A mild deter-
gent is very helpful.)
If a large water tank is available, the radiator
can be submerged, and a check for air bubbles
can be made.
REPAIRABLE LEAKS
There are two types of leaks that can be repaired
on the aluminum-plastic radiator: core leaks and gas-
ket leaks. Leaks in the plastic tanks cannot be
repaired.
RUBBER
TEST CAP
OIL
COOLER
PLUGS
- « S 0 0 0 3 - 6 B
Figure 11 Aluminum Radiator and Oil Cooler Plugs
Core leaks can occur in a tube, or in the joints
between the tubes and headers. Gasket leaks can
occur in the joints between the plastic tanks and the
headers, or in the joints between the oil cooler fittings
and the tank. Some leaks can be repaired while the
radiator is on the car; however, it is usually best to
remove the radiator.
[Y]
INLET TANK GASKET
[J] CORE TUBES
[J]
OUTLET TANK GASKET
4 ] DRAIN COCK GASKET
T] OIL COOLER GASKETS
JOINT BETWEEN TUBE A N D HEADER
H20004 6B
Figure 12 Possible Leak Areas