Gen1 Coolant overflow tank

[Ckerch]

I just bought my first gen Riviera and trying to address some of the issues with it. It is a 1964 425 base engine with Air Conditioning (doesn't work). From what I can tell the radiator looks like it has a 4 row with horizontal tanks and trans cooler built in. When it is running, I don't see any antifreeze leaks but later on I see a pool of antifreeze. I am thinking that it is coming out of the overflow so I thought I might add a overflow tank. However, I am not sure of the size needed or where to put one. I think I could put a 1 liter one next to the battery but when doing some of the calculations found on the internet, I comes up needing a little over 3 quarts in size. This is based on 18 1/2 quart capacity and using 12% draw down and 6% expansion calculations. This just seems a little large. 

 

Has anyone installed one and what size did you use?

Also, where did you put it?

 

Thanks in advance,

Carl

[Seafoam65]

                You are seeing the coolant on the ground after you shut the car off because it superheats and expands

and comes out the overflow hose. All you have to do to prevent this is leave room for expansion at the top of the radiator when filling

it with coolant. It will find it's own perfect level if you stop adding coolant when it leaks out. If you do decide to add a recovery bottle,

be aware that the cap for the radiator will have to be changed out to one for a closed system that has the extra rubber seal on it.

[RivNut]

Are you using a cap with the recommended pounds of pressure?  

[Bill Stoneberg]

I had the same issue on my 64 until I learned that you dont fill the radiator full when cold.  I ran about an inch down cold and my radiator puking antifreeze on the ground days were over.

The car will find the level it is happy with.

[Ckerch]

As I just bought this vehicle, I don't have much history with it. Actually, I am waiting for the registration to come back from DNV so I can drive it. So I have only doing very limited driving. 

The antifreeze is on the ground and a little bit was on the lip of the top tank of the radiator. When I looked in the radiator, there was no antifreeze in the top and it took about 1/2 gallon to fill it to half way between core and top of the tank. 

 

I should have looked at the obvious and looked at radiator cap first. The one in it is only 13 lbs rated. I believe the correct pressure should be 16 lbs. Hopefully that is the problem. I'll see if the local parts supplier has one.

 

Thank You

Carl

[KongaMan]

My car was fitted with an overflow bottle when I bought it.  IIRC, it's a Buick washer fluid reservoir mounted to the inner fender between the horn relay and the hood hinge  (it's a well done job).  I've never gotten around to removing it, but in 40+ years I don't ever remember seeing any fluid in it.

 

I've always filled the radiator to just cover the tubes.  That seems to leave plenty of room for expansion, and I could probably still go a bit higher.

[TexRiv_63]

I did not do this with my Riv but starting with my 63 Olds Starfire I have added a coolant recovery system (NOT an overflow) to the last three of my hobby cars. All you need is a new VENTED cap of the proper pressure rating, some rubber hose and a suitable plastic tank. This is like most newer cars and allows you to fill your radiator to the top, the vented cap then allows the heated fluid expansion to move into the tank and draws that same fluid back into the rad as it cools. No overflow problem and a bit of extra cooling capacity. For some reason a lot of people fight against doing this for some reason but it makes sense to me.

[Seafoam65]

Another aspect of the recovery system that is a benefit is that because the system is always full to the top, there is no

oxygen in the system which tends to breed corrosion if the coolant isn't changed out often.

[Ckerch]

I still do like the thought  of a recovery system for the reason TexRiv and Seafoam stated. I make since to keep the air out of the system. I ordered a new radiator cap to see if that fixes my coolant leak/overflowing. Thanks Rivnut for pointing me to that.

TexRiv and Seafoam, do you know the size of the recovery tank you are using?

 

 

Thank You

Carl

[telriv]

Depending on the size of the system one to two quart capacity seems to work well.

[Ckerch]

I bought a Slant 10230 non vented 16 lbs radiator cap to fix my immediate for now but I know when I install the overflow/recovery tank I will know I need to also change the cap to a vented one like Slant's 10231 16 lbs cap. However that cap or other ones that are vented say they do not fit the 64 Riviera. I assume that is only because the Riviera did not come with a recovery tank and a vented cap and not because the radiator neck changed.  Is that a good assumption ?

What brand or model number are others using?

 

Thank you

Carl

[Seafoam65]

The 10231 should fit. O'reilly's sells a very nice coolant recovery bottle that consists of a wire cage that

screws to your inner fender or radiator support and the bottle snaps in and out of the cage for  easy removal to clean it out

if needed. It holds about two and a half quarts of overflow which should be plenty. It is made by interdynamics part no. BVR-4

I have one of these on my GTO and it works great. I don't have a recovery bottle on my Riviera at the present time......I'm keeping it bone stock

in all respects. I had to put one on my GTO because it has a 455 Pontiac motor which tends to run pretty warm in the summer

with the A/C on and it kept popping off on me when I shut it off after driving so installed the bottle to catch it when it does that.

The Riviera runs so cool that I haven't had any issue with overflow as long as I leave space for expansion in the top of the radiator.

Edited August 15, 2019 by Seafoam65 (see edit history)

[KongaMan]

The one I have is similar to this:

 

 

It's sold as a replacement for a 64-69 Chevelle.  This particular one is sold by OPGI, but you should be able to find something similar from a less risky vendor.

[60FlatTop]

I haven't needed to put an overflow or recovery system on any old cars. They find their level and work fine. When I have any doubt about puking antifreeze I put a temperature gauge under the hood and watch it, as well as other underhood cooling components. Two of my cars have gauges mounted under the hood now.

 

Since the car is new to you the brakes should be thoroughly checked to be sure they are not dragging. I have seen everything from small parking puddles to transmission fluid boiling from dragging brakes, Peel back the wheel cylinder boots and look for thick brown mud. Check the hardware for age pitting on the springs and lack of lubricant. You should be able to park the car level, stick your foot out the door, and push to make it roll from a standstill.

Bernie

[Ckerch]

Thanks for the recovery tank suggestions. With only having tell tale lights instead of gauges, it make me more sensitive about overheating. I think that will be my winter project.

 

It has been a while since I drove a car with all drum brakes. They feel a little soft but I am not sure if that is because I am used to disc brakes. I will try you trick about moving the vehicle and at least pull them apart and do a visual inspection. Along the brake inspection, thought about putting in a dual reservoir master cylinder. Not sure about that though. 

 

Thanks again

Carl

 

[Seafoam65]

They should not feel soft........4 wheel drum brakes have less pedal travel than any disc brake car because the tiny wheel cylinders

versus big caliper pistons require much less pedal travel to activate the brakes because less fluid has to move. My Riviera has a very miniscule pedal travel.

You probably need to change out the master cylinder and wheel cylinders and brake hoses if they are old and be sure to use silicone brake fluid to

eliminate future hydraulic problems.

[RivNut]

You first might try just having the brakes bled.  

[KongaMan]

2 hours ago, RivNut said:

You first might try just having the brakes bled.  

Given that he just bought it and it has a (presumably) unknown maintenance history, I'd suggest a thorough inspection would be the first order of business.  If it were me, I would (at a minimum) replace the front and rear hoses as a matter of course and take the master and all the wheel cylinders apart to look for sludge and corrosion.  The three hoses are cheap (<$25 for all three), as are the wheel cylinders (~$40 for all four).  Bleed them once before you replace anything (just to flush the lines), then bleed them again after any new hardware has been installed.

[Garysriv]

Put mine right behind the battery.  Made an L bracket and mounted to core support and inner fender.  Works great!

[Ckerch]

I received my new radiator cap 10230 from Slant and it did fix the overflowing issue. Now I have a very slight leak at the top tank were is soldered. Not sure if I can resolder (touch up) or need to take it to the radiator shop. It was rebuilt in 95 roughly 3000 miles ago. 

 

However, I am a little confused on the radiator cap. According to the Slant spec's, the 10230 cap is supposed to be a standard cap and the 10231 is a vented cap. But from the picture, it looks like it has a vent for an overflow tank. Am I correct and could this be used with a tank?

 

Thank You

Carl

[Seafoam65]

 I'm not sure about the differences in the lower section on closed system versus open system, but usually

the open system caps only have the lower rubber seal, not the second seal in the roof of the cap like your photo.

Edited August 19, 2019 by Seafoam65 (see edit history)