The Stovebolt Site Forums The Shop Area General Truck Talk Coolant overflow tank

I'm curious if a coolant recovery tank was a dealer item for a 46 Chevrolet pickup.? The truck is still owned by it's original owner. He told me that the truck came with it.
Thanks Don
https://picasaweb.google.com/101285...Gv1sRgCP7ewfrooYyEdw#5604379541318024706
https://picasaweb.google.com/101285...Gv1sRgCP7ewfrooYyEdw#5604379326056099538

Dang, sure looks to be dont it. I would say it was but to tell you the truth I have no idea.

I can't believe it would have been stock in 46, considering the rad caps that early were zero pressure and lower temperature, but on the TF series that exact looking item is listed as an RPO in the accessory manual for export only, and not on the available accessory list

Bill

The 1946 Chevrolet truck might well have come from the dealer with a radiator "Overflow Return Tank" (on any truck other than the COE) but it would have been a dealer installed GM accessory (not an RPO).

The Heater Shut-off Valve (shown in the Picasa photo #4) was also a 1946 GM accessory.

The coolant tank shown is very similar in construction to the tanks used on Canadian Military Pattern trucks from 1941? to 1945. Although the construction is similar, the proportions look taller and thinner than I'm used to seeing on those Chevs. They were also a no/low pressure system. The CMP Fords also had coolant recovery tanks, but they were a completely dirrerent shape.

Grant,

Your information and observations are quite interesting. The tank in the Picasa album looks thinner and taller than the tank shown in the 1946 USA Chevrolet Truck Data Book. Also, the label on the TDB tank is white with dark lettering. The lettering on the Picasa-album tank looks like it was stencil-painted (as if it might have been a military issue)?

1.290 Condenser Unit, radiator overflow
1937-48 All (exc. COE) 985528 $2.95.
Would have been a dealer installed accessory. Looks like it might be original to the time period also. I believe the later ones, 986282 had a decal rather than the screen printed lettering.
Tim, any chance of your posting a scan of that '46 data illustration. All I have avalable are the reprints the vendors sell, '49 and '54 copyrights and the '54 doesn't show any illustrations.

That looks like a real nice original truck I hope you’re planning to preserve it. It would be a shame to upgrade it. You should document everything that you can on a find like that. Keep the pictures coming.

It’s hard to believe the condition of that heater shutoff valve. If it were one of the newer steel ones or one of the repop ones that the vendors sell it would be all rusty with in a year or two.

Denny Graham
Sandwich, IL

I figured that it was a dealer installed item and not built that way on the assembly line. When I talked more with the owner of the truck he said that he had traded another pickup in on this one but the '46 came out of the dealership as is now. I would guess that most dealerships in this part of the country when ahead and included a heaters and other accessories as they felt needed for the climate and just included it in the price. Don

Here is a link to a photo of an NOS overflow tank. PN 985528
NOS Overflow Tank
This is listed as 47-55
Mike

The part numbers for the Chev CMP tanks were 5805402 and later 5819685 depending on the mounting location (early was exposed, later hidden). Both parts are identified in the parts book as being unique to the Canadian military production.

The Canadian tanks I have been able to measure are 6-5/8 diameter and 8-1/2 tall. I don't know whether they are the exposed or hidden tank. I also don't know for sure how the two tanks differed.

I'd bet on that tank being military production.

The illustrations in Truck Data Books might not have been updated properly by GM every year, but, assuming that they were, here are some illustrations from USA Chevrolet Truck Data Books:

1946 pre-Advance-Design - OVERFLOW RETURN TANK (supposedly available since 1937)

1947 Advance-Design - OVERFLOW RETURN TANK

1949 Advance-Design - notice the change in the name of tank "OVERFLOW CONDENSER"

Just wondering if the coolant tank will work with the standard Radiator cap as you have to have one that has a vaccum valve as well as a sprung loaded one. Or its just a catch tank , As it wont be able to suck fluid past the sprung loaded seal when the pressure drops.

Great pictures of those NOS items Mike, thanks for posting them. And thanks to you Tim for those illustrations. I would tend to agree with you about the accuracy of the pictures in the data books. The decal in the ‘49 data book is similar to the reproduction decals the vendors are marketing, which appear to be a copy of the later ones as Tim pointed out, i.e. ’49-‘55 “Overflow Condenser” rather than “Overflow Return Tank“. This later one is shown in The Filling Station’s catalog. Chevs of the 40’s also lists this one with no illustration and they also list one for 1939-48 but again, no illustration. Looks like I’ll have to buy one of each to see what they are copied from. I’ve yet to see an illustration in the data books or any reproductions of the silk screened lettering that appear in the actual photos that Don and Mike posted. Seems to me that I saw a repop decal of that a while back but I can’t remember who was selling it.

I've been wondering about that return for a long time also Ryan. It seems to me that there would have to be a two way cap since the over flow tube is above the seat in the neck. I've never been able to figure out how the coolant in the overflow condenser could get back to the radiator tank. There had to be some special cap that was used with the overflow installation.

Denny Graham
Sandwich, IL
(You'r to quick on the trigger Tim, I'm still editing...)

These 1951 installation instructions (truck) show how the radiator cap is "adapted" for the "Overflow Condenser". Notice that the words are not on a label - they looked painted (or maybe a clear background decal)?

Similar instructions (but no photo) are found in the 1954 Accessories Installation Manual.

Can someone explain how pressure is maintained, how the overflown fluid returns, and the function of the inlet and outlet hoses (is there a valve/diaphragm inside the overflow tank)?

-----

I have a NOS 986282 Radiator Overflow Condenser (with original/unused installation parts, instructions, and original box). The lettering is painted on. The lettering is a dull/dark red that does not contrast well with the color of the tank. This unit looks just like an illustration in the Chevrolet Ready Reference - 1954 Edition - Passenger and Truck". I'll try to take a photo later today.

Notes:
986643 is the part number for the 1953/1954 USA car/truck Radiator Overflow Condenser.
986282 is the part number for the 1951/1952 USA car/truck Radiator Overflow Condenser.
985528 is the part number for the 1947-1949 USA car/truck Radiator Overflow Return Tank.

I do not have part numbers for the 1950 USA unit, but it was called a Radiator Overflow Condenser" (probably 986282).

Okey Dokey, I tink I got some of it figured out.
This is the standard 4lb cap that any of the vendors carry:
http://www.pbase.com/dennygraham/image/134622685
These two pictures show the ins and outs of the cap:
http://www.pbase.com/dennygraham/image/134622711
http://www.pbase.com/dennygraham/image/134622717
There must have been an upper gasket included in the Overflow accessory package to seal the cap at the top of the neck. Easy enough to make one up though.
I’d sure like to do an autopsy on one of those tanks to see the insides. I’m sure many were simply thrown away when they rusted out even today. Fabricating one to look like an original would be a simple matter if you had the dimensions and knew what the inside looked like. I suspect that there may be a stand pipe of some sorts in there because of the two pipes. I don’t know why they would need an inlet and an outlet because there is no circulation involved. All that would be needed is to blow it in and suck it out.
Denny Graham
Sandwich, IL

Based on the Canadian military tanks, one of the tubes goes to a pipe within the tank that comes up into the small hemisherical dome at the top of the tank. This dome is a second part soldered (?) to the top of the tank that has three(?) small vent holes between the main part of the tank and the small compartment under the dome. My understanding is that this is an atmospheric vent with the second pipe being a short stub that lets fluid from the radiator enter (and return from) the tank.

Denny,

Thank you for your analysis/interpretation.

Grant,

Thank you for your autopsy report.

Now, what do you think the differences in the part numbers might relate to? My guess it that the differences are not due to the style of label (white label vs painted words). However, the differences may be due to name on the label (Radiator Overflow Condenser vs Radiator Overflow Return Tank) and due to change in pressure cap rating in 53/54?

resurrecting this old thread as i just ordered a tank so was doing some research.


a standard radiator cap is used with the condeser tank, the only difference is with the original caps they werent intended to be used with a return system so when the radiator cools the vacuum generated could draw air from both the overflow pipe and leak in from around the top of the cap.

when you use the condenser tank you now want all that vacuum to go towards sucking back the overflow so this is why you are advised to add a gasket seal to the top of the radiator cap if one isnt fitted. that way the only thing your sucking back in is the overflow



i think....


original tanks were lead lined to prevent corroding thru i guess.....i wonder if the repros are....