six blade fan and expansion tank on a ´68?

[Kell Oskarsson]

Hello all,

a couple of nerdy questions

I have been going through the cooling system on my ´68 SDV and noticed two things on my car that look original but do not match the specs in the literature:

1) I have a six-blade fan, not seven. It has the thermal coupling and this is a car with factory A/C.

2) The radiator has an expansion tank, mounted on the driver´s side next to the radiator. The tank as well as the mounts look to be about as old as the car. However, from what I´ve understood, the coolant recovery system was not introduced on Cadillacs until the 1969 model year. I´ve also not come across any indication that this was available as an option, or installed by dealers.

Any ´68 owners out there with the same setup?

Best,

Kell.

[DeVille68]

I have a 68 with A/C,  7 blade and no expansion tank.
Only explanation I have is that the previous owner made these changes?
But I guess it does not hurt the Caddy at all. If it works - leave it.

[Scot Minesinger]

The expansion tank was started in 1969, but see no harm in adding it.  I would leave it.

If your car does not overheat in 95'F weather with a/c on and sitting in traffic idling, then probably a good idea to leave what is in place alone for the fan.  However if you got to have authenticity buy a genuine 1968 Cadillac fan for a/c and install it, retaining the former set up.  Then see if it works as well, if not switch back.  You keep the authentic fan and switch it out at GN, then put it back to drive home.

[bcroe]

I installed overflow tanks (and other cooling enhancements) on my 60s
cars.  I was so glad I did, when I saw them saving my coolant, instead of
it running out onto the pavement.  Keep it. Bruce Roe

[TJ Hopland]

So why did they start adding the tanks?  Was it just not classy to possibly have your car pissing coolant on the ground or did the EPA finally say they had to do it?   I suppose part of it could have been by the 70's cars were getting to the point you didn't have to be under the hood as often so maybe they were seeing cars running low.  Maybe topping off the coolant was one of the things you did when you were in there filing points and adjusting you brakes?