Draining and filling the cooling system (Sierra)

Since the 1985 model, the thermostat housing has been equipped with a nipple used to bleed air from the cooling system. This nipple is closed with a threaded plug.

Draining the fluid and filling the system

1. When removing air from the cooling system, unscrew the air bleed pipe plug.

2. When filling the system, this plug is screwed in before the system is finished filling, when the coolant begins to flow out through the fitting used to remove air.

[The full article is on the online resource: FORDBOOK]