The cooling systems is a closed system with the resiviour part of that system. Coolant is added to the resiviour cap. This is different from other cars as the resiviour is not usually pressurized. In the s-series it is.
behind the radiator
Regular green stuff.
The way to replace the thermostat on a 91 Acura Legend Coupe is to drain the radiator and remove the throttle and cable box. Remove the top of the radiator hose and the bolts. The thermostat will be inside.
Try the original not worth upgrading
on the top radiator hose.
Live-In - 1989 The Coupe the Group and Everything 1-2 was released on: USA: 27 March 1989
It is on the radiator side of the engine, under the engine mount.
The 1958 Ford Coupe cost around $2,000 for a Custom model and $2,400 for a Fairlane 500 Coupe.
If it's repairable, a reputable radiator shop will be a good resource. They can tell you if the radiator can be repaired or if it must be replaced.
The thermostat is under the housing where the lower radiator hose attaches to the engine.
2.5L V6 it is under the housing that the lower radiator hose hooks to on the engine.
To replace a radiator on a 1991 Thunderbird Super Coupe, a person has to drain the old radiator, then unhook all of the hoses. The radiator is bolted to the cross beam in the front and held in by bolts and screws along the sides and bottom. It is a good idea to take a picture of the old radiator and hoses to use as a reference when installing the new one.