66 Eldorado

[John Mreczko]

HELP! HELP needed! To all members, Did you ever start a project and then try to finish it and you can't remember how it goes back together? I need to know how the heater hoses are supposed to be connected.Which one goes to directly to the radiator? Does one get connected to the brass nipple on the water manifold? Should the heater control valve be inline on the "top" hose or the bottom? If you have familiarity with the 66 Eldorado (or 65) and can help me resolve this, it would be greatly appreciated.Also, what should I do about one fitting that doesn't want to screw back into the radiator for the transmission cooler.Your help will get another Caddy back on the road.

[Otto Skorzeny]

Run a thread chaser into the radiator. Clean up the fitting, too. The outer thread probaly got pushed in or something.

No experience with 66 hoses, though.

[Ralph Messina CLC 4937]

John,

There are two hoses…3/4 and 5/8’ I believe. The ¾ exits the rear side of the crossover pipe just below the thermostat housing, passes to the rear of the oil filler tube, crosses under the AC compressor, beds toward the heater box and connects to the upper heater nipple. The 5/8 hose exists the radiator and connects to the front side of the water control valve. It exists the WCV from the rear side and attaches to the lower nipple on the heater box. If you have the seat warmer option, there is a copper valve in the 5/8” line between the radiator and WCV.

I would use  Otto’s advice to clean the trans cooler line fittings.

HTH,
Ralph