Well Ron: What I did on my 69 was to take the windshield washer bottle which I believe was original and used that for an antifreeze overflow bottle. Just bought a new repo washer bottle and installed that in it's original location. I took the old bottle and bought an extra holding bracket (made for that bottle)and mounted those between the battery and the passenger fender. Can't really see it unless you are looking for it and the routing for the overflow was a short run.

 

You would not need an overflow jug if you fill the radiator to the proper level. Look on the rear of your radiator and see if it has the fill line marked on it. The line is 3.5 inches below the filler opening. Or, just fill it so it covers the transmission cooler ( if so equipped).

 

having a functioning overflow tank at the proper level with the proper cap helps keep the cooling system in better shape by not having any air sitting in the empty space at the top of the radiator where it can cause corrosion. it also allows a little bit of a "cushion" to allow the engine to not boil out excess coolant if it runs hotter than normal for some reason... it's a good thing to have, and the only penalty for having it is a white plastic jug sitting next to the battery and the weight of about 2 quarts of extra coolant.

 

Overflow bottle from an mid-'70's Nova (I think...) will slide behind the battery and be virtually invisible. (Downside: Impossible to inspect and to fill without removing the battery.)

That's what I'm using on my '68, anyway.

 

X2 used that on my car when I go the dragstrip

 

I've used a 2nd gen Camaro overflow setup in a few Chevelles...do a SEARCH for GM part numbers...cost about $20-25 and looks "factory".

 

i thought they had overflow tanks standard by then?
my 71 Nova had one and it looked pretty damn stock to me- so maybe 71 Chevelles did, too..

 

My 71 is all stock under the hood and there's no overflow tank.

 

X3 on the mid 70's Nova, I'm using that too.
Jim

 

I am using a 3rd generation F body bottle setup on my 70. It fits on the fender and is GM, but obviously does not look original since they never had them to begin with.

 

Ron, Did you switch out that 195 degree t-stat? If not, I would give it a try before adding a bottle. JMO

 

I installed a overflow catch on my '71 Chevy 4x4 pickup I restored. Used a w/s washer tank and bracket, mounted it on the pass. side near the battery. Looks stock and functions quite well. I also changed out the stock radiator cap for a newer flip-up release lever for a closed cooling system. Plan on doing the same to my '71 Chevelle when I get to that point in the re-build.

 

Ron, if you go the route that Brad suggested, the cap from the overflow bottle on a mid 80s Toronado fits the windshield washer bottle and has 2 hoses on the lid, one from the radiator and one as the overflow out of the bottle. I attached a picture of it to a thread some time ago. Here is the link - http://www.chevelles.com/forums/showthread.php?t=384229.

 

In the original post , it was stated that he wanted to keep the car original looking. Adding a later model tank is not consistent with that. Just reverting to original specs for coolant fill would satisfy his needs, I think.

 

THanks Guys!

Will check my levels...probably filling too high...

Troy-didnt switch out the stats yet...just been driving her ALOT...and running through antifreeze in this hot weather! its on the list...

I put a third gen Fbody reservoir on my clone...but wanted something more period correct/less obvious for now...

I will look into the bottle thing kind of cool...

what was stock, a glass bottle? or nothing?

 

The original system had a rubber hose that went down toward the road; there was no container for coolant overflow. The hose is shown in the factory assembly manual. ( part nr 3153359)

 

...and a radiator tank that's probably stamped with a "fill to this level" line or arrow, about 2--3 inches BELOW the rad cap opening.

Thus the beauty of the overflow tank: It (slightly) increases the cooling capacity of the radiator, because with the rad FULL, the top few rows of tubes are actually useful, instead of merely filled with air.

 

just because no one's pointed it out yet (i think), you will need an overflow/catch can on the car if you ever want to run it on an NHRA sanctioned track.

 

I bought a cheap overflow kit from AutoZone (about $10) and put it behind the battery. You cant even see it and it works.

 

Our GM bretheren(Buick)had this as an option in 68-69 and standard starting in 70 model year-this is a repro piece but you get the idea and its a GM design. A little spendy and that 3rd gen Fbody unit Tom is using looks close for probably way less $$

Available from the thepartsplaceinc.com

Marc S

 

AWESOME INFO!

thanks guys! I will check it out this weekend!

BTW...prob wont do NHRA track stuff...yet...

R

 

Mine is a cheapo hung on an existing screw (no drilling and all original parts saved) forward of the radiator support. They left a big hole to run a tube from below the cap to it, and I use no tube from it.(Pricked the other top port so it vents...it never vents fluid.) Can see level through the grill w/o lifting the hood. (Could paint it all flat black but for a masked vertical sight stripe.)

It is a squarish tank, and the smaller of the two you'll find at Pep Boys or Walmart or somewhere.)

 

Hey guys,

I am trying to keep my Chevelle very stock and original...but I need an anti-freeze reservoir!

Any ideas on one that keeps it close to original with minimal drilling?

thanks,
Ron

Your words^^
That one doesnt look original to me.
To each his own.

 

thanks for the info!

So besides antifreeze puking...and it settling about 2 inches from the top...and cooling temp ok...when does it warrant an overflow?

any other sign that coolant is low besides running hot???

besides providing more cooling capacity and obviously more coolant, what is the functional use of an overflow? just cleaner?

thanks guys!

 

the overflow keeps you from wasting coolant, and it keeps air out of the system when the engine is cool. air can cause things to corrode.

 

I think that the closed system with the overflow bottle got started in about 1973 or so, when emissions controls boosted engine temperatures. Higher temperatures tend to reduce unburned hydrocarbon emissions. With higher coolant temps, the amount of expansion of the coolant probably became an issue. Thus the tank. I worked for car companies back then and saw coolant temps of 220F in some test runs and that was considered OK. As stated , a side benefit was reduced corrosion potential, but if the correct antifreeze is used, it would have effective corrosion inhibitors.

 

JW great info!

I changed to 160 degrees t stat. will hopefully be able to test drive it in a couple days...(got called into office...darn work-always seems to get in the way)

Looking into reservoirs...have a buddy that might have that glass overflow, which will be an easy trade...

thanks,
R

 

I have a 70 Chevelle and mounted a round plastic aftermarket overflow bottle between the radiator and the front grill support just below the left horn. Not original obviously but rather hidden and effective.

 

I must be looking at the wrong places, because I can't find an overflow tank that looks like the one Tom has in his pic.
Can someone point me in the right direction??