Heater core hose hook-up

[BUONO]

I just changed the core out on my 1987 5000TQ.   It you used a new or
aftermarket heater core it very well might have a one way check valve to
control directional flow of coolant to prevent air pockets from building up
in the cooling system.  Hook it up as per Bentley.  The new core I bought
came with a memo to inform me that the "rattling" in my core was normal and
part of the flow control valve. 
 
-F