Will22

I am looking for the complete radiator overflow set up, the jug, bracket and cap for my 1972 Cutlass Supreme convertible.

Thanks
Will

Allan R

They are reproduced now. Cost is about $200

Will22

Thanks Alan. Do you know if these were factory installed in 1972? It shows in my CSM.

Allan R

No, they weren't factory installed. They're not even listed in the 72 RPOs.
The overflow reservoir was a solution to the overheating problems encountered by the 455 back then. The reservoir was a no charge install at a dealership. It was available to any Olds owner who wanted it installed. If your car doesn't suffer from overheating or spewing coolant when hot, you probably really don't need one. I have one (OEM) in my car as it tended to overheat especially in slow moving traffic. If your car has AC, it likely has heavy duty cooling so wouldn't need the overflow unless you have a 455 in it now.

Will22

Thanks for the information. I do have A/C on my car and it is the original 350 Rocket. It overheated some the other day in 100F temps when I was cruising. I am going to change the antifreeze, thermostat and radiator cap. While I am at it, I am also going to replace the upper and lower radiator hoses...the upper one felt a little spongy. I was going to install the overflow then too but since it wasn't a factory item, I am not going to do it.

Again, thanks!

Fun71

If you are not concerned with originality and a concourse type setup, you can get a generic overflow tank kit from any auto parts store. I got one for about $18 at O'reilly Auto parts:
https://www.oreillyauto.com/shop/b/c...utlass-supreme

Allan R

Overall, that's a very good approach to the issue. When you say it overheated some, what does that mean? Do you have a temp gauge? On hot days it's not uncommon for the temp to climb to around 200 or so. Usually when the heating system gets on the hot side and it hasn't before, it means that something needs attention. The areas you're targeting are the correct places to focus. Coolant does break down over time - make sure to use the right concentration for best operation. Open the radiator cap and look inside to see if it has a buidup of crud that may be inhibiting coolant movement. It's not hard to take out and have flushed/pressure tested either. Rad hoses will feel a bit spongy when they're warm. Look at that connections and specifically whether the hose clamp areas look bulged out. It certainly won't hurt to change out those hoses, especially if they're old.

Kenneth,
If the OP is concerned with originality, that would mean no overflow. But your suggestion is a good one with a practical price tag.

Will22

Alan, I do not have a temp gauge. When I got home, coolant was leaking from the overflow tube. The coolant looks good but am going to replace it. The upper hose was spongy even when cool and id buldging a little at the hose clamps. Car is performing good, no sign of oil in the coolant and no sign of coolant in oil. Im leaning towrds a bad thermostat or cap.

troyd

Seems like overheating is a rabbit hole with no end....

If you add an expansion tank, like the repop setup, you will also need to switch to a different type radiator cap. Everybody probably knows that....but I didn't (I'm an idiot so there is that) so just in case there is someone else out there as challenged as I am....

Just my .02 but adding a temp gauge is a worthwhile and easy project.....

Cheers,

Troy

Fun71

This is normal operation and does not necessarily indicate the engine was overheating. On non-recovery cooling systems, the coolant level needs to be at the mark on the radiator tank to compensate for expansion when the engine is hot. The line is ~2" below the top of the tank. If you had the coolant filled too high, some would escape when the engine got up to operating temp.

Will22

thanks. However, it expelled more than just a little bit. Probably about 20% of the coolant that was in the radiator. That's why I'm going to change out the thermostat and the radiator cap.
QUOTE=Fun71;1112425]This is normal operation and does not necessarily indicate the engine was overheating. On non-recovery cooling systems, the coolant level needs to be at the mark on the radiator tank to compensate for expansion when the engine is hot. The line is ~2" below the top of the tank. If you had the coolant filled too high, some would escape when the engine got up to operating temp.[/QUOTE]

Allan R

Interesting what a missing square bracket ( [ ) will do to a quote