REMOVAL & INSTALLATION
See Figures 1 through 12
Fig. Fig. 1: Locate and loosen the cooling system draincock valve ...
Fig. Fig. 2: ... allowing the coolant to drain into a catch pan
Fig. Fig. 3: Loosen the upper radiator hose clamp, then detach the hose from the neck
Fig. Fig. 4: Remove the waterneck retaining bolts ...
Fig. Fig. 5: ... then lift the waterneck off the cylinder head
Fig. Fig. 6: Remove the thermostat form the recess in the cylinder head
Fig. Fig. 7: Scrape the old gasket material from the head-L-head 4-134 engine shown
Fig. Fig. 8: On F-head 4-134 engines, remove the waterneck hold-down bolts ...
Fig. Fig. 9: ... and lift the waterneck from the cylinder head
Fig. Fig. 10: Remove the used gasket with a scraper, if necessary
Fig. Fig. 11: The gasket must be removed, because the thermostat is mounted under the gasket
Fig. Fig. 12: Pull the thermostat out of the cylinder head-F-head 4-134 engine shown
The thermostat is located in the water outlet housing at the front or on top of the engine. On the 6-225 V6 the water outlet housing is located in the front of the intake manifold.
When draining coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.
To remove the thermostats from all of these engines, first drain the cooling system. It is not necessary to disconnect or remove any of the hoses. Remove the two attaching screws and lift the housing from the engine. Remove the thermostat and the gasket. To install, place the thermostat in the housing with the spring inside the engine. Install a new gasket with a small amount of sealing compound applied to both sides. Install the water outlet and tighten the attaching bolts to 30 ft. lbs. (41 Nm). Refill the cooling system.