Anti-Foam Agent in Radiator

[Guest sndtubes]

I have a 1930 Buick. I've posted here before about overheating, etc. One of the problems I solved was that if I filled the radiator too much, it would foam and run out the overflow. The solution was to just not fill the radiator much over the coils.

I was talking to a friend of mine and he mentioned he had exactly the same problem with his 1929 Buick. His solution was quite interesting and I wanted to run it by you all before trying it. He put some Rug Doctor anti-foam agent into the radiator and can now fill it nearly completely without it foaming and overflowing. This stuff is used to keep the detergent in the Rug Doctor machines from foaming too much and causing overflowing, etc.

My questi is have any of you heard of this or used it yourself and do you think this stuff could harm the radiator or engine?

[JohnD1956]

Why would the radiator of a 30 and 29 Buick foam when others don't? Unless you have virulent water pumps on those cars, this sounds like there is some airpressure pushing into the radiator. Perhaps a small or pinhole leak in a head gasket?

JD

[Mark Shaw]

Our 29 Buick did this too, until I stopped using antifreeze. I have not tried Rug Doctor additive.

First try plain water filled to just cover the core. If you still get air into the coolant, it is more probably due to a starved pump suction causing the pump to cavitate. This can be due to a plugged radiator core or a collapsed hose.

Replace your hoses first (it is less work and the lower cost solution).

To test your radiator: Remove it from the car. Stuff a rag into the bottom outlet so it will hold water. Fill the radiator to just cover the core. Tilt it with the bottom outlet up at 45 degrees. Remove the rag & see how far the water shoots out. If it shoots less than two feet, you have restricted flow through the core & will need to have it rodded out or replaced.

[D Binger]

You might check and see if air is being sucked into your cooling system. A good place it start checking is your water pump. It will suck air but not leak water. AIr being sucked in through the water pump will cause foam and overheating. I had a Model A Ford doing that until I repacked the water pump and I have not had a problem with foam on the radiator since. A couple of other folks have done the same thing. The car won't overheat as easy when there is no foam in the cooling system also.

Dan

[mlander]

Go to #444420 to find more problems! http://forums.aaca.org/ubbthreads.php/ubb/showthreaded/Number/444420#Post444420

M.L. Anderson

[Guest sndtubes]

Well, the water pump is rebuilt. The radiator core is new. And the engine has been rebuilt with the water jacket thoroughly cleaned and the block boiled out. I went ahead and tried the anti-foaming agent and it works great. Now if I fill the radiator most of the way, there is no burping out the overflow pipe. I will be having the water pump reworked this winter with the neoprene seal trick so I won't have to worry about that any more. The packing still leaks at the pump even though it has been recently repacked and I tighten the nut every time I see it leaking some.

[Mark Shaw]

Did you repack the pump with graphoil square packing?

Just don't use teflon! It will eventually score the shaft.

[tblack]

Using the search feature of this forum I put in the word foaming. Buicks that I have owned always to some degree have been foamers and water leakers. The latest is my 1923 Model 49 Buick. I admit that my concentration of anti freeze is a bit too high. My water pump leaks some. I would find like others that unless I kept the level low in the radiator the foam would pushout at high RPM. With foam I was running a bit warmer than I would like at only 60F.

So I said what the hell...I bought a bottle of Rug Doctor Antifoam agent added to a gallon of water and topped off the antifreeze radiator. I took a brisk 40mph ride up the back mountain with a 500ft ascent no foaming and ran very cool. Idled the car for a few minutes no leaks. When I turned the car off the front packing on the pump leaked a little more than normal but a tighten and the leak stopped . My limited trial of rug doctor produced a noticeable improvement. They put anti foaming agents in some antifreezes.

Be curious to hear from others that have used it for a longer period of time

[Morgan Wright]

Regular ethylene glycol antifreeze foams a lot, period.  Just do this test. Take a plastic water bottle, put in 4 ounces water, and then an ounce  of antifreeze. Put the cap on and shake the bottle...…..foams like heck. Now do the same with water and denatured alcohol. No foam.

 

Maybe we should be using alcohol as antifreeze, like the owners manuals say, instead of regular antifreeze. And add a little anti-rust to it.

 

This chart is in the 1918 Buick manual, I added centigrade temperatures for our friends in, like, everywhere.

 

temperature F...……….temperature C...…………..alcohol

 

........10...…………………………….-12...……………………...20%

……...5...………………………………-15...……...……………...30%

..20 below ...……………………..-29...……………….……..40%

..35 below....……………………..-37...……………….……..50%

[Morgan Wright]

I'll winter it in regular antifreeze because it doesn't evaporate, but for spring and summer switch to denatured alcohol.

 

In the summer, I'll just use water and the anti-rust. No foam with pure water. I don't think these water pumps are designed for modern foamy antifreeze.

[Morgan Wright]

In the old days, they used alcohol as antifreeze in the winter, maybe a little in the spring and fall, depending on the climate, and plain water in the summer. I have seen it in all the old movies, etc. You would see the guy low on water, mechanic comes with the water can to fill the radiator. You would never bother adding alcohol in the summer, why would you? It evaporates much faster than water, why not just use water? 

 

I see no reason to ever use modern antifreeze in these old cars, except for winter storage or long-term storage where multiple winters are involved, and then, why not just drain the coolant and use nothing? Air doesn't freeze.

 

But always use lots of anti-rust: https://www.amazon.com/gp/product/B07GQ5XC8M?pf_rd_p=183f5289-9dc0-416f-942e-e8f213ef368b&pf_rd_r=3ZHVZKWMJNKZPV42XPGM

 

[Hubert_25-25]

My fill point with a radiator is always just above the radiator core.  The header tank provides no additional cooling and you need the space for expansion.  I don't want to put antifreeze in, just to have it come out the overflow tube.  I am not sure what is in your antifoam, but as long as you can maintain the system level and keep the core flooded, it's not a big problem to worry about.    Hugh

[Morgan Wright]

I don't use anti-foam. I use anti-rust. 

 

My point is, these old cars don't need ethylene glycol antifreeze. It foams like crazy with these fast impeller water pumps, and was never used in the old days, it wasn't even invented yet. If you use plain water you can fill the radiator all the way, not just to "above the core" because the upper radiator tank was designed that way for a purpose, it is a reserve to make sure you always have enough water. If you keep your upper tank empty to avoid foaming, and fill to the top of the core, what happens when a little water evaporates? Now you don't have enough water. I say, use plain water with anti-rust in the summer, add alcohol the rest of the time......….it never foams and you can fill the upper tank of the radiator all the way, the way it was designed to be.

 

My car is a no ethylene glycol zone.

[Terry Wiegand]

An engine with anti-freeze in the coolant will run a few degrees cooler plus the anti-freeze acts as a water pump lubricant.  In my humble opinion it is not a good idea to drain the coolant out of the block and then let it set dry even for a short while.  This is an excellent way to promote rusting in the water jacket.  It was mentioned earlier that there is an anti-foaming agent in the anti-freeze solution.

 

Terry Wiegand

South Hutchinson, Kansas

[Morgan Wright]

1. Why would antifreeze make the engine run cooler than pure water (with anti-rust)? Water has the highest specific heat of any liquid. 

2. Agreed about not draining it for storing. Antifreeze for storage is best.

3. Water doesn't foam. Neither does water/alcohol. Antifreeze foams.

4. The anti-foam agent in rug shampoo is not going anywhere near my car.

[Morgan Wright]

Product	Specific Heat - cp -
	(kJ/(kg K))	(Btu/(lb oF)) (Kcal/kg oC)
Acetic acid	2.043	0.49
Acetone	2.15	0.51
Alcohol, ethyl 32oF (ethanol)	2.3	0.548
Alcohol, ethyl 104oF (ethanol)	2.72	0.65
Alcohol, methyl. 40 - 50oF	2.47	0.59
Alcohol, methyl. 60 - 70oF	2.51	0.6
Alcohol, propyl	2.37	0.57
Ammonia, 32oF	4.6	1.1
Aniline	2.18	0.514
Benzene, 60oF	1.8	0.43
Benzene, 150oF	1.92	0.46
Benzine	2.1
Benzol	1.8	0.43
Bismuth, 800oF	0.15	0.0345
Bismuth, 1000oF	0.155	0.0369
Bismuth, 1400oF	0.165	0.0393
Bromine	0.47	0.11
n-Butane, 32oF	2.3	0.55
Calcium Chloride	3.06	0.73
Carbon Disulfide	0.992	0.237
Carbon Tetrachloride	0.866	0.207
Castor Oil	1.8	0.43
Chloroform	1.05	0.251
Citron Oil	1.84	0.44
Decane	2.21	0.528
Diphenylamine	1.93	0.46
Dodecane	2.21	0.528
Dowtherm	1.55	0.37
Ether	2.21	0.528
Ethyl ether	2.22	0.529
Ethylene glycol	2.36	0.56
Dichlorodifluoromethane R-12 saturated -40oF	0.88	0.211
Dichlorodifluoromethane R-12 saturated 0oF	0.91	0.217
Dichlorodifluoromethane R-12 saturated 120oF	1.02	0.244
Fuel Oil min.	1.67	0.4
Fuel Oil max.	2.09	0.5
Gasoline	2.22	0.53
Glycerine	2.43	0.576
Heptane	2.24	0.535
Hexane	2.26	0.54
Hydrochlor acid	3.14
Iodine	2.15	0.51
Kerosene	2.01	0.48
Linseed Oil	1.84	0.44
Light Oil, 60oF	1.8	0.43
Light Oil, 300oF	2.3	0.54
Mercury	0.14	0.03
Methyl alcohol	2.51
Milk	3.93	0.94
Naphthalene	1.72	0.41
Nitric acid	1.72
Nitro benzole	1.52	0.362
Octane	2.15	0.51
Oil, Castor	1.97	0.47
Oil, Olive	1.97	0.47
Oil, mineral	1.67	0.4
Oil, turpentine	1.8
Oil, vegetable	1.67	0.4
Olive oil	1.97	0.47
Paraffin	2.13	0.51
Perchlor ethylene	0.905
Petroleum	2.13	0.51
Petroleum ether	1.76
Phenol	1.43	0.34
Potassium hydrate	3.68	0.88
Propane, 32oF	2.4	0.576
Propylene	2.85	0.68
Propylene Glycol	2.5	0.60
Sesame oil	1.63	0.39
Sodium, 200oF	1.38	0.33
Sodium, 1000oF	1.26	0.3
Sodium hydrate	3.93	0.94
Soya bean oil	1.97	0.47
Sulfuric acid concentrated	1.38
Sulfuric acid	1.34
Toluene	1.72	0.41
Trichlor ethylene	1.30
Tuluol	1.51	0.36
Turpentine	1.72	0.411
Water, fresh	4.19	1
Water, sea 36oF	3.93	0.938
Xylene	1.72	0.41

[Matt Harwood]

Forget water, I'm running ammonia in my radiators!

[27donb]

3 hours ago, Morgan Wright said:

1. Why would antifreeze make the engine run cooler than pure water (with anti-rust)? Water has the highest specific heat of any liquid. 

2. Agreed about not draining it for storing. Antifreeze for storage is best.

3. Water doesn't foam. Neither does water/alcohol. Antifreeze foams.

4. The anti-foam agent in rug shampoo is not going anywhere near my car.

 

The experience of my father and grandfather driving these cars for years of trouble free miles, along with my own experience of doing the same thing, is why I always use 50 /50 water and antifreeze mix all year long.  

 

By driving within the limits of the car, never had an overheating problem, no foaming, and as long as the radiator is not over filled, no overflow problem.  Ever. 

 

Antifreeze is a good rust inhibitor and water pump lubricant. 

 

Antifreeze and water won't allow an engine to run cooler, but it can allow an engine to run hotter before boil over, provided the mixture is under pressure.  So the only advantage with the old Buicks is, rust inhibitor, water pump lubrication, and anti freezing through the winter. 

 

Efficiency with this old technology is marginal by today's standards.  Push these cars to today's traffic standards, drive at 50mph or higher, drive on the highway, drive in sweltering hot conditions, drive with a partially clogged radiator or water jacket, leaky air sucking water pump that needs repacking, and EXPECT to overheat. 

 

My 2 cents... 

Edited August 22, 2019 by 27donb (see edit history)

[Jim Milewski]

Very interesting article all of my pre-war friends, I wish my problem was just foaming, I own a 23-6-48 Buick (featured in the Dec issue 2016 of the Bugle as a refresher) I have had over heating issues, too many, two days ago (after having health issues) I started the 23 and was very happy as it fired with one key turn (hadn't been started since July 2018 in Gettysburg) - well it boiled over on me, the radiator had been cleaned years ago, and previous conversations with my dad indicated that the water pump was never worked on - soooo I removed the cover plate and exposed the impellor - yup you guessed it, not much there - this is where I need help in replacing it, does anyone know of a reliable fabricator? Any and all ideas are welcome, I will be removing it based on previous posts, as for now she sits on jack stands in the barn - thanks in advance  J, Milewski Jr. PS will be at the Buick Nationals in Strongsville with my 65 Riviera, will look all of my pre-friends up 

[Grimy]

I'm sure I've described this experience on other parts of these forums.  When I first acquired my 1934 Pierce 13 years ago, it had a fresh water pump rebuild (modern seals and bearings, no more packing), a recored radiator, new hoses, 50% EG coolant and a purged block--all within the previous 500 miles.  Note that all Pierces have UNpressurized cooling systems.  Enroute to a PAS Meet 6 weeks later, at every pit stop, I had to add at least a gallon of coolant.  In unpressurized systems, EG coolant can OFTEN foam even without a pump sucking in outside air.  The foam displaces coolant space in the top tank, so that coolant being delivered to the top tank is pushed out the overflow.  (Of course, whether there is a diverter in the top tank under the cap can have an effect as well.) And at highway speeds (55-58 mph on that car), there CAN be a siphon effect at speed.  Long story short, straight water in the system resulted in virtually no coolant loss under the same conditions.

 

Fortunately, in the SF Bay Area I don't need anti-freeze, so I run water + a anti-corrosion (not just anti-rust) / water pump lube additive.  For more than 10 years I've happily run Pencool (Pencool 2000 for no anti-freeze, Pencool 3000 for any amount of anti-freeze), an additive made by PenRay Corp primarily for big rigs and stationary engines.  This product was formerly known as Nalcool.  I had some email discussions and phone calls with a  helpful PenRay chemist a couple of years ago, who is a car guy with a 1968 Charger.  I buy Pencool on Amazon (very hard to find retail in my area) in the 64-oz (half-gallon) jug size which is most convenient for me.  Initial dosage is 1 oz Pencool for each quart of cooling system capacity.  The periodic refresh dosage rate is 20% of the initial dosage at 15,000 miles or 300 hours.  That Pierce, and several others with unpressurized systems, now go at least 700 miles per quart of coolant top-off. I carry a one-gallon jug of water pre-loaded with 4 oz of Pencool.

 

If you have an exposed radiator cap (say, pre-1933), top off only when hot OR fill to just above the core.  Often a diverter blocks view of the core.  When radiator fillers were first moved under the hood (1934 and newer Pierces, and also my 1934 Buick of happy memory), the angled filler neck is at the very top of the radiator, so you MUST only top off hot.

[Matt Harwood]

I'm running the permanent Evans coolant in my '29 Cadillac without incident, although I agree that it does not transfer heat as well and the car runs slightly hotter because of it. However, if your cooling system is so close to the edge that using anti-freeze pushes it from "OK" to "overheating" then you have a bigger problem. The Evans doesn't foam, and I did have a foaming problem with regular anti-freeze and simply didn't know about it until I installed a radiator cap with a mascot (i.e. it has a hole in the top of it). I've been pleased with it overall and I like the fact that it does not corrode dissimilar metals (there's aluminum, iron, copper, and brass in that cooling system), it is good to well below freezing and to like +300 degrees on the high side. I don't drive the Cadillac as much or as fast or as far as I used to, so I never really stress it, but it has a radiator the size of a Kenworth's and has always run at 155-160 degrees (165 or so with the Evans)

 

My '41 Buick runs ice cold too, like 160-165 under most operating conditions and never above 190 even idling in traffic on an 85-degree day. I'm loathe to mess with anything in that car's cooling system, even though the water pump is a little noisy and there's some seepage at the joint between the top tank and the core. I'm going to tackle those issues this winter and hope it still cools as well in the spring, and I think I'll try distilled water and the Pencool that Grimy is recommending. The Evans coolant is fine, but as I said, it's not as efficient with heat exchange and this is a car we really drive hard and fast so the more robust I can make the cooling system, the more reliable it will be. I'm going to try it and hope my shop doesn't lose heat and freeze during the winter...

[Terry Wiegand]

As all of the pre-war guys know, Hugh, Larry DiBarry, and myself have posted on another thread about our engine rebuilding experiences.  One of the points that I have mentioned about my rebuild is the fact that I had the cylinder block 'thermally cleaned'.  Looking inside the water jacket through the freeze plug openings I could see that the surfaces looked just like what was on the outside of the block.  I am totally convinced that this process is the way to go during a rebuild of an engine.  My Dad used to run distilled water and a product called Rust-Master in his John Deere Two-Cylinder Tractors.  These engines used thermo-syphon cooling systems.  No water pumps and non pressurized.  He would always drain the coolant in the late Fall.  I run the Original Formula Zerex 50-50 Premix anti-freeze in the 1920 and 1922 with no problems ever.  I believe that the anti-freeze solution allows for the engine to run a few degrees cooler than just plain water, it has an anti-foaming additive, acts as a water pump lubricant, and has a corrosion inhibitor additive.  The original formula Zerex is safe for the old vehicles with white metal components - solder, brass, copper, and aluminum.  I do not know much about these other coolants that have been mentioned here.  I do remember my Grandfather telling me that back in the very early days of T Model Fords people used to run Kerosene in the cooling systems because permanent anti-freeze solutions had not been developed yet.  The radiator on our '16 D-45 is as close to a brand new unit as possible.  I am not real keen on the idea of spending close to $3,000.00 to have a new radiator made for this car.  I am 100% convinced that there will be no problems whatsoever when this engine goes back together.  All that I can say at this point is that this is my story and I'm stickin' to it.  OH, the last very important detail is that the water pump for my engine has been rebuilt using a new cast brass impellor that I got from Dean Tryon.

 

Terry Wiegand

South Hutchinson, Kansas

[Morgan Wright]

[Morgan Wright]

My car foams like crazy with 50/50 Prestone, leaves green milkshakes along the side of the road, neighbors dogs come drink it and die, and then my car overheats.

 

My car doesn't foam at all with plain water, drove from Maine to Spain and lost no coolant, car runs cooler than Miles Davis at a Carrier factory jam session in Antarctica. 

[Larry Schramm]

I have been running a 50/50 Prestone in my '15 truck for the last maybe 5 years.  I do not get any over flow, foaming that I know of and every time I check the coolant it is always above the core by maybe an inch or so.  It also does not run hot.  I think there is something else going on in your cooling system.  I will continue to use EG in my cars for a number of reasons which most have been stated above by Terry & others.

Edited August 23, 2019 by Larry Schramm (see edit history)

[stvaughn]

If you like reading here is a patent from February 12, 1935 for a antifoaming agent for antifreeze applications that mentions automobile radiators so the problem and the solution pre-dates me and I suppose most of you folks too. Now if I just knew what Montan wax was I could make my own. 

 

https://patents.google.com/patent/US2127490A/en

 

Steve 

Edited August 23, 2019 by stvaughn
Added comment (see edit history)

[Morgan Wright]

No wonder my water jacket was so caked up with montan wax, lard, and castor oil. 

[stvaughn]

Yea, but talk about rust protection....😳

[Grimy]

I like Terry Wiegand's idea of thermal cleaning IF an engine is torn down to that level, but for engines running satisfactorily I prefer to attempt simple solutions (no pun intended) first.

 

Larry Schramm, I'm happy you're having excellent results with 50/50 Prestone.  Others have not, and my comments were directed to those in search of a fix and were not, I believe, couched as Universal Truths To Be Believed by All the Faithful.  There are many variables--cruising speeds, original core vs recore, even ethanol vs non-ethanol fuel, to mention just a few.

 

Last month I changed out all the coolant hoses on my 1930 Pierce after 9 years and 5.000 miles (I believe in changing all hoses periodically) and replaced the stocking filter which had absolutely minimal debris in it.  The old coolant itself and the visible portion of the top tank were sparkling clean.  This car has also been running on Pencool for that period.  I will indeed continue to use this product, with which I have no affiliation other than as a very satisfied customer.

 

On another car, my 1922 Paige, I had massive overheating problems which I hope have now been cured.  The car was refurbish-restored almost 50 years ago in Iowa, where I am told, there is an issue with lime and other naturally occurring contaminants in the water.  This was exacerbated by the previous owner's obsession with soluble oil for cooling systems--repeated chemical flushing resulted in much "slime" being caught in my stocking filter, and the soluble oil inhibits heat transfer.  I've also removed the core plugs in the head and have cleaned it out.  The radiator is vee-ed with herringbone fins as a prominent styling design feature, and a new core would cost as much as the car is worth.  I had the radiator tanked and it appeared to weigh a few pounds less when I picked it up!  We'll see--over the winter I will be reassembling after a valve job, and replacing the wiring harness.

Edited August 23, 2019 by Grimy
added 3rd paragraph (see edit history)

[Steve_bigD]

I had severe foaming with EG coolant which turned out to be a cracked cylinder head at the rear two cylinder exhaust valve seats.  The coolant would virtually blow and bubble out of the overflow tube after a high speed run. After replacing the head I still had a bit of foaming with EG and the car would run cool until a sustained highway drive where the temperature would slowly rise up to over 200 deg.  This turned out to be a partially clogged radiator and after re-coring the radiator the foaming is totally gone. I use standard Prestone EG 50-50 and keep the radiator tank filled about 0.5-1" over the top of the tubes. I have yet to add coolant in two years and it runs 170-180 all the time. 

 

I think that EG coolants tend to foam if agitated enough and air injected into the system (cracked head leak) or a backup in the radiator causing agitation can cause foaming. If the cooling system was in factory new condition I am sure EG coolant would not foam.  To be safe and account for a not so perfect system condition pressurizing the system to 7lb. should suppress any slight tendency to foam. This can be done by removing the metal overflow tube and soldering the opening closed, then changing the filler inlet to a pressure type with a built-in overflow tube port.  A rubber tube can be run from the port down the original overflow tube clips.  I plan to do this soon.

 

As an aside, for every pound of pressure, the boiling point of the coolant will rise by about 2 degrees. A 50-50 mix of EG will boil at about 226 degrees at sea level pressure so with a 7lb. cap the boiling point will be 240 degrees.  This gives a nice margin of safety.

Steve D  

[Mark Shaw]

This is a very old thread.... 

One more thing to consider is a restriction on the suction side of the pump that causes cavitation & results in foaming.. 

The restriction can be caused by corrosion in the engine block, but is more often due to a collapsed hose. 

New hoses usually have a spring shaped wire inside to prevent this.

 

[Terry Wiegand]

Please forgive my ignorance here, but, what in the world is this EG coolant that is being talked about?

 

Terry Wiegand

South Hutchinson, Kansas

[stvaughn]

Ethylene glycol 

[Terry Wiegand]

Thank You.

 

Terry Wiegand

South Hutchinson, Kansas

[Morgan Wright]

Evans is propylene glycol, almost the same.

[Morgan Wright]

I bet the radiator hoses don't last very long with water/denatured EtOH mix, I know that stuff eats rubber.

 

EtOH meaning...….Et means ethyl and OH is the alcohol symbol, all alcohols end with OH, the symbols for oxygen and hydrogen

[raydurr]

I have had the foaming over experience with my 1929 Buick. I ran coolant at different levels to no avail. I did notice when the engine was running at fast idle how violently the water was circulating inside the radiator. The factory thermostat had been eliminated years ago. I added an inline thermostat from restoration supply to the upper radiator hose. Immediately no more foaming over at road speed. The best I can tell the system needs a restricted , controlled flow to prevent aeration of the coolant.

[Morgan Wright]

Scratch Mac's 1300 Anti-rust...…………….it foams!

[stvaughn]

1 hour ago, Morgan Wright said:

Scratch Mac's 1300 Anti-rust...…………….it foams!

 

Not in my REO.

 

I’ve been following this thread with interest. I got my 32 REO sedan drivable this spring and I’ve put almost a thousand miles on it with distilled water in the radiator while I worked out the bugs. Friday I changed over to NAPA green EG and a bottle of Mac’s 1300 anti rust. I’m happy to report absolutely no foaming issues whatsoever in 70+ miles of driving, some of it pushing the REO harder than I really want to. (55 mph). 

 

YMMV, Steve 

[Morgan Wright]

1 hour ago, stvaughn said:

 

Not in my REO.

 

I’ve been following this thread with interest. I got my 32 REO sedan drivable this spring and I’ve put almost a thousand miles on it with distilled water in the radiator while I worked out the bugs. Friday I changed over to NAPA green EG and a bottle of Mac’s 1300 anti rust. I’m happy to report absolutely no foaming issues whatsoever in 70+ miles of driving, some of it pushing the REO harder than I really want to. (55 mph). 

 

YMMV, Steve 

 

What sort of water pump do Reo's have?