Anyone have a suggestion for a good coolant overflow tank for a '68? I’ve come across some other threads that referenced stainless steel tanks that seemed to work well, but I’d like something that at least looks vaguely period correct. Is there a specific size/capacity that anyone has found works best, or does it not really matter? Right now I’m just looking at universal tanks like this one
My current temporary fix was an old milk jug, zip tied behind the driver headlight assembly. But it recently started leaking, so I figured it’s probably time to get something permanent.
I use the hard plastic windshield washer reservoir from a '68. Run the radiator overflow hose to the bottom - where the washer fluid would come out. Just don’t mix them up!
Thanks for the suggestions! I actually thought about repurposing another washer fluid tank, but I didn’t think I’d be able to get it to fit next to my existing one. The JAZ tank looks like it would fit nicely. I did notice my milk jug was close to half full at the highest point, so I may need to see if they have a 2 quart version.
I saw a reference about having to swap out the radiator cap for one from a later car designed for a cooling system with a factory overflow tank. Is that accurate? My existing cap could stand to be replaced, but I didn’t seem to have any issues with the coolant not being able to return to the radiator.
As I recall the overflow kits came with a cap w/o a pressure relief lever or ‘ears’ to aid in twisting it off. I believe this was because it was considered a ‘closed system’ and the cap was to keep Joe Customer from messing with it since you were supposed to add coolant to the overflow tank, not the radiator.
I do not remember if the pressure rating was different. I have always run a 14 lb regular old lever type cap on my cars - but I like messing with things.
I think this tank was a Speedway item…about a quart…made some alum clamps to grab the orig tabs.
Not a great space to mount but the easy space next to the washer res was taken by circut breakers and relays.
With a small tank , I added a ball valve below the coolant inlet at the bottom to drain the tank if too full.
Its worked great since 2008.
I like this, This would blend in nicely under the hood for sure. Only down fall is not having a cap.
I have used the other styles posted here and they work nicely as well. Sometimes the caps can get stuck on them and they are kinda tall so fitting them in a cramped space is a challenge
I like the idea of using the passenger fender area, mounted to the area behind the battery. That would give the most room for a tank, and there is even a body plug I could remove to run the hose through. The only downside is not being able to see the tank from under the hood, although a short walk to the wheel well is certainly not a huge issue.
I had an ‘overheating’ issue last year - gauge said the car was running hot at highway speeds, but then would cool down once I was around town or idling (which is the opposite of how I understand cooling airflow works). The coolant did initially vent from the radiator cap/bypass hose, but after installing the milk jug overflow tank, the car never actually overheated, despite the gauge continuing to read hot at higher speeds.
There is an NOS ( which translates into $$$$ ) coolant recovery container / tank for sale on eBay right now ( July 04, 2023 ). For sale from MagMustangs in Washington, state. I’ve dealt with Andrew and he is very good / knowledgeable and packs up his sales very well. Downside is it is always pricey.
Here is the description in case the link goes funny on you : “1967 1968 Mustang GT GTA Shelby Cougar Xr7 Gte NOS WINDSHIELD WASHER RESERVOIR” and the ebay listing # is:155639383881
I’m relatively new here so forgive me if I repeat old news. '60’s Ford big blocks had an expansion tank, the recrangular container attached to the thermoastat housing and the upper hose. It had a baffel plate mid height that was the fill level, leaving “expansion” room in the tank. Using that thought I fill my radiator just to the top of the cores leaving some “expansion” room in the radiator. I have a '67 Cougar with a 390, 4spd. 4bbl and no power equipment. Since I did that I have not had an issue with coolant loss. Rick in Morro Bay.
Here is the overflow/recovery tank I installed in both my 69 Cougars. I previously had the polished aluminum recovery tank like others have posted but never liked it under the hood. This is a simple Dorman overflow/recovery tank that I located inside the right front fender. It’s out of the way and works perfectly. All I had to do was create an aluminum bracket to mount it to the back side of the headlight structure.
Here’s another eBay listing for a 1977 ( at least that’s what the part # ‘decodes’ for ) Lincoln coolant recovery tank - a lot cheaper than the Cougar NOS one earlier in this thread
Thanks for all the great ideas. I decided against putting it next to the washer fluid tank due to space/mounting surface limitations. I found a universal 2 quart tank at the local parts store and went with mounting it under the passenger side fender for now (mostly since I had the fender off at the time anyway):
It’s a bit tight to access the fill cap if needed, but I figure I can always add via the radiator too. I haven’t gone for a lengthy test drive yet, but from going around the block it started to fill a bit on its own.
The location is decent. I mounted my transmission oil cooler (forced air) in that same area. I used some gutter guard screen sections to provide protection from any sort of large projectile that could be kicked up in the wheel well.
Amazon of all places has a bunch of tanks…aluminum and plastic , that would work ok on either side of the core support . Some even looking kinda factoryish.
