Radiator Overflow Tank

[aero3113]

Just curious if anyone uses a overflow tank? If yes what do you use? Any Pics?

[greg g]

Nope just the tube down the side of the radiator. Once the system has established its working level, it has never been an issue. Do not over fill the radiator, about 1/2 inc of collant over the fins is about where they will run. If you fill it too full, it will over flow and the you will be tempted to thik yo need ot refill it. Just let it burp out what it doesn't want and leave it.

[BobT-47P15]

True, it seems to seek it's own level.

However, for the HAMB drags back in 05 when I ran the Plymouth

down the strip for fun, I used an empty Miller Lite can as an over

flow tank to meet regulations.

I think it's still there, but doubt it has seen much water.

[oldodge41]

My '41 with the flathead does seek and maintain a level just as Greg described. On my '69 Dart with a slant six the level would never stabilize. For all the years I have owned it, and before according to the receipts from the previous owner, it would go most of a summer spitting out a little every time I parked until it would start heating up from lack of coolant. I put an overflow tank on it and expected it to keep spitting out until it would overflow the tank but it didn't. After a full summer of cruising the radiator never spit out more than the tank could handle and I never needed to add coolant. I used one I bought from ebay like this. http://cgi.ebay.com/ebaymotors/2-X-17-STAINLESS-SS-RADIATOR-OVERFLOW-TANK-6324-_W0QQcmdZViewItemQQhashZitem4cf32a27c8QQitemZ330497140680QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories Easy to find a place for it to mount and could be painted if you don't want the bright finish. My .02...... Tim

[blucarsdn]

I am a firm believer in overflow tanks for the cooling system.. When the overflow tanks first started to appear on the GM cars/trucks in the late '60's i started using them on all of my vehicles.

The theory of an overflow tank is very simple, heat expands, cool contracts. A cooling system that is not full has a tendency to gather air in the system, i.e. air entrainment does not allow the coolant to function properly.

The use of an overflow tank purges the air from the system while at the same time allowing the coolant to expand into the tank, not onto the ground, then when the coolant cools it is drawn back into the radiator.

Of course a recovery type cap must be used on the radiator otherwise the coolant will escape around the cap in lieu of into the overflow tanks. On older radiators a 3 or 4 pound cap works well, new radiators usually use 17 pounds.

I usually make my own tanks out of 2" ABS plastic pipe.

A piece of pipe 18" long, 2 plastic caps. cement one cap on, leave the other loose.

2- 3/8" 90 brass elbows, drill a 5/16" hole in the bottom cap. thread one brass 90 into the cap.

Drill a 5/16" hole in the side of the tube about 2" from the top, thread in 90.

Using clear 3/8" tubing, attach one end to the bottom 90 elbow, attach the other end to the radiator overflow. attach a piece of black tubing to the upper 90 elbow.

Locate the overflow in a vertical position neat the radiator, attach with plumbers tape or large hose clamps to the inner fender, etc.

Partially fill overflow tank, fill radiator with coolant, start engine. When the coolant expands into the clear tubing you will have a visible indicator in the tubing. When the engine is turned off the coolant will be drawn back into the radiator, refill the tank to about 1/2 way.. Place cap on overflow tank.

When you check your engine look at the overflow sight tube, no coolant in tube, system is low add coolant to overflow tank.

I like the black ABS plastic because it is requires no painting and won't rust....Bill

[Don Coatney]

I am a firm believer in overflow tanks for the cooling system......Bill

Are you using the original radiator in your car?

[james49ply]

I had a problem of losing water from my 48, I took a hose from the overflowtume and ran it to a bottle, then I installed a rubber spacer into the cap neck to seal it to allow the fluid to overflow into the

reservoir when hot and be able to suck the fluid back to the radiator as it cooled. the radiator cap must be sealed to prevent air from entering during the cool down time. Engine now runs cooler and I don't have to add any coolant. also use the 'wetter water'.

[Frank Elder]

I had a problem of losing water from my 48, I took a hose from the overflowtume and ran it to a bottle, then I installed a rubber spacer into the cap neck to seal it to allow the fluid to overflow into the

reservoir when hot and be able to suck the fluid back to the radiator as it cooled. the radiator cap must be sealed to prevent air from entering during the cool down time. Engine now runs cooler and I don't have to add any coolant. also use the 'wetter water'.

Can a non pressurized system "suck" water back into the radiator....real question here, not poking fun at anyone.

[Don Coatney]

Can a non pressurized system "suck" water back into the radiator....real question here, not poking fun at anyone.

Yes if the cap is sealed, the overflow tube is submerged, and there are no air leaks in the system.

[Frank Elder]

Thank you Don, I guess it woud be good if you were bothered by the thought of your rad puking on the floor of your garage.

[Booker T]

I recently had some work done to the original radiator in my 54. Along with this work I had asked the shop to re-weld the tube down the side of the radiator and also reposition it because I wanted to add a "cool looking" overflow tank.

I was told that my style of radiator was not supposed to use an overflow tank. This may be becase of the radiator cap type (or the position of where the cap seals in relation to the overflow tube). I was told that using a tank could also cause problems if there was enough overflow into the tank and it filled up past the bottom of the tube. I don't remember the exact explanation of the scenario this would cause...I just went with their advice and had them weld the overflow tube back into the original position.

[Dan Hiebert]

I put an overflow tank in my D-24 when we were in El Paso, TX many moons ago, after we had the car for a year or two. Didn't like the coolant overflowing onto the driveway. Just used a generic one from Pep Boys. The car has never overheated, and never lost coolant while running, but after driving around in the good ole southwest climate it would overflow after parking and turning the car off - no airflow or circulation to dissipate the heat. Sometimes it would be hot enough in Texas or New Mexico that it would overflow just parked in the driveway if I had topped it off recently. Funny, since moving to Michigan and New York, haven't had that problem:rolleyes:

[blucarsdn]

Are you using the original radiator in your car?

The radiator in my '39 Plym is a Davis Racing three row aluminum. The radiator is meant to be a cross flow, for a Ford, we stood it up which puts the fill neck on the right side and the inlets/outlets in the correct location for a belly button small block. I have a 16 lb recovery type cap on the radiator.

The radiator in my '57 T-bird is an original style as is my 37 GMC with a 292 CID 6 cyln... My '36 Ford has the radiator that came in the car when new.

I have found that 3-4 lb caps work well on the older style radiators, that is if the radiator, etc., is in good shape.

Until about two years ago I had a '63 Chrysler 300 with a 383, I built one of my home grown overflow tanks out of ABS, hooking same up to a stock radiator running 50/50 coolant and 15-16 lb cap... The system worked great...Bill

[Powerhouse]

I used an old milk bottle, cork and a hose. Works but I need to get more hose since the liquid evaporates easily and goes lower than the hose.

I have seen ww1 canteens being used...but I couldn't see drilling into the cap. Why ruin the canteen? Unless it already is ruined. I am still looking for a somewhat busted canteen to use.

Edited January 21, 2011 by Powerhouse

[Reg Evans]

I'm with Greg. I have several old L-6 powered MoPars and once the radiator spits out the over filled amount nothing leaks out again winter or summer. The old radiators aren't made to hold pressure.