"Snuffy "Hub Cap" McKinney" wrote in message
...

Back to the 97 Aerostar again.... It appears that the heater core is nearly
plugged. Some heat gets through, but not much.

Heater valve & vacuum work fine. A friend said to pull the valve off and
connect a garden hose to the outlet and hit it with some short blasts of
from the garden hose. Then connect to the inlet and repeat until it flows
free and clean.

But, and this is a big butt, I have done these kind of things before and
been sorry later. So I thought I'd ask the online brain center for some
(good) advice first. The last thing I want to do is open a leak in the core
and hose down the front seat.





Heater Core Back-Flushing

All engine cooling system flushing and back-flushing procedures must include
a separate back-flushing of the heater or air conditioning system heater
core (18476), after the flushing or back-flushing of the engine cooling
system.

The correct back-flushing procedure for heater core is as follows:

Disconnect the heater core outlet hose from the water pump fitting and
install a female garden hose-end fitting adapter in the end of the outlet
heater hose. Secure with a hose clamp.

Connect the female garden hose end of the outlet heater hose to the male end
of a water supply garden hose.

Disconnect the heater core inlet hose from the engine block fitting and
allow to drain into an appropriate container.

Check to be certain the water valve is open (no vacuum) if a water valve is
installed in the heater core inlet hose.

Turn the water supply valve on and off several times so that the surge
action helps to dislodge larger stubborn particles from the heater core
tubes. Allow full water pressure to flow for approximately five minutes.

Apply vacuum to the water valve vacuum motor, if a water valve is installed
in the heater core inlet heater hose, to ensure proper operation of the
water valve and proper closure with no water leakage. Replace the water
valve if required.

Remove the hose clamp and female garden hose end adapter from the end of the
outlet heater hose and reconnect the outlet heater hose onto the water pump
fitting.

Connect the inlet heater hose onto the engine block fitting.

Fill the cooling system. Refer to the procedure in this section.

Test the system for proper heater performance with the specified engine
cooling system conditions.