VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Radiator flushing advice

I have a 1936 master deluxe 4 door with trunk. I just got the car this past summer and have about 700 miles on it. It seems to run a little on the hot side. I put in a new 160F thermostat and replaced all the hoses. That seemed to help a little but it still wanted to run around 180 to 190f. I decided to pull the water pump and inspect it. It had been leaking around the pump shaft badly no matter how much I adjusted the packing nut so it needed new packing anyway. While I had all the hoses off the radiator and the water pump removed, I took my new USB boroscope and looked in the top of my radiator. Things look pretty caked up in there (rust and calcium?) and it looks like only the middle passages of the radiator are open. I looked in the block through the water pump opening and although the surfaces are rusted, everything looks open. I don't have a lot of money. I know replacing the radiator would be the best solution but is there an effective in car solution? Do any of the coolant system flushing products at the auto parts stores work? There aren't any radiator repair shops here in Lynchburg that will touch something this old. Is there an affordable repair shop that I can ship this too near Lynchburg Va.?

Back in the '70's or so there were two brands of cooling system cleaner that worked. One was in a silver container and sold by DuPont, the other in yellow and sold by Prestone. The cleaner was in one end of the container and a neutralizer in the other end. Through the years the EPA did't like the stuff and it is no longer available.
I still have several cans and always kept some in the trunk on my cars so when we traveled with a group I could help out guys when they had a problem.

Also at one time Lye cans had instructions on the can for cleaning radiators.

The "modern" radiator cleaners sold today are usless for disolving rust.

find an old rad repair shop with an old guy with a beard in your area, they are out there. He will know what to do. Take the top tank and bottom tanks off and have them cleaned them properly and checked for flow.

If you play with old cars , sooner or later its going to hurt your beer and tobacco money supply.

mike

You need to know the art of shaming these shops that don't want to do their job when it comes to older cars! If they are a real radiator shop, yours is no different than a newer one.

The problem as I found out a couple of years ago is that most of these shops no longer build radiator cores.. They order in one brand new in a box and install it. That's the problem with modernization .
Similar problem with carburetor rebuilders, uuuuuuuuuum whats that, all they taught us in school is fuel injection > Try visiting a GM dealer and see what response you get when you ask for a non electronic distributor and carburetor rebuilding. Points, what are those ??? The look on their dumbstruck faces.

Let me get my laptop and see if I can reconfigure your FI for you.

As they push us towards driverless cars, be wary and same applies to electric cars. All their supposedly great ideas pushed by the bean counters........remember the chevette and the Pontiac AZTECK , GEO and others.

mike lynch

There are products out there that may help a bit but a proper old school rad shop cleanup is the best. I think I would still want to flush the block BEFORE getting the rad cleaned so you don't contaminate it again.

You should be able to find a commercial cleaner that can work like the old rad cleaners. We use a product at work called Dairy Kleen to clean steam boilers and small parts that have mineral deposits. It literally washes away heavy deposits in a minute or two on most items. Do your homework on compatibility as I've never used for this application. http://www.chemfax.com/default.aspx?pageid=894

If it were mine, rad would be going to a shop. While it's gone I'd jury-rig a way to soak and flush the block with something strong. Do a search on here for proper block cleaning. I'd then neutralize anything added and rinse, rinse, and rinse before rad comes back.

In Auto shop in school the best radiator/block cleaner was SANI-FLUSH crystals. He said it was the best but if things were held together by rust you would surely find out.

First thing I would do is remove lower hose and thermostat/upper hose. Chock rags around a garden hose, turn on full force and REVERSE FLUSH the block. Then go the other way. When it runs clear water put it back together and see if you have made improvement. Then you can try the other things if that don't work. Just a Mule Headed Farmer's advice from Mississippi.

TERRILL.................I think that's more than great advice when combined with some kind of internal cleaner and run for a while hot. Then flush fwd and back again.

In the end it all boils down to clean block passages, clean radiator core, water pump that's sealed and cannot draw air and finally the most important , a fan other than stock that draws large quantity of air thru the rad core at idle and can hold a cloth diaper to the grill mesh at 600-700 rpm.

mike lynch

I would say the large fan shouldn't be needed if you get the cooling system up to par.

While I agree with all the removing and cleaning suggestions if it were mine I would first use the flushing and a good acid cleaner method. If the engine did not overheat, just ran on the warm side cleaning should help,

A heck of a lot easier than removing the grille shell, etc, to get the radiator core out.

PHIL Lipton ( milln phil ) did a test on this site of his findings using a 34-36 truck fan that has a different pitch to the blades and how it flowed more air thru the radiator and effected the cooling ability .

Its in this section in the last 2 years.

The ability of the engine fan to draw as much heat out of the radiator as possible goes a long way towards proper cooling.

The biggest problem constantly written about in this group is overheating .

mike lynch

I agree with cleaning the system as suggested above and if you still have not solved your overheating issue I would go with a better fan blade.

I have owned my 1933 Master since 1971 and it always overheated and several of the solutions reduced the issue, but did not totally get rid of my overheating problem. The last thing I did was replace the original fan blade with a 1933 Chevrolet truck fan blade that is just slightly larger in diameter, but the blades are significantly wider and blow a lot more air. I don't remember how many years the truck fan was made, but as I recall it was from 1932 thru 36. Took several years for me to find one.

The new fan blade completely solved my over heating issue.

I would remove the block petcock located on the driver side below the intake/exhaust to allow crud a larger hole to drain out of. If you have compressed air it helps to dislodge crud in the block when filled with water and blowing into block openings.

A 1936 engine was well cooled in stock condition. If it runs hot installing a larger fan blade is only covering up the problem. That being said it would be normal for it to run at 180 deg. if the outside temps. are above 90 Deg.

And you could install a 160 degree thermostat, too. These 1936's will maintain proper temperature even on the hottest of summer days. Here in Mississippi the hot humid conditions really can test a cooling system. Crud in a system that has been in storage for several months is what causes them to fail. Annual "Spring Cleaning" is a must before the "Driving Season" opens up.

I used a cheap endoscope to look in the radiator. I couldn't get it in the bottom tank but was able to get in the top tank. Looks like the outside channels openings have a rust build up in them and there is a calcium looking build up between them. The center openings look like they are open. I had already installed a new 160 thermostat when I started trying to cure the issue. It helped a little but I still run around 180 to 190 out on the highway.I have pictures but haven't been able to figure out how to post therm.

The original radiator has a sprinkler device in the top that sprays the water to the openings you are looking at. The top tank has "head space" or an air space to the water level. This allows the water to spray ensuring "even" flow to all the tubes. Look up with your endoscope and see if you are not plugged up on the sprinkler. Reverse flow the radiator and check the flow out of the top tank. This may also clear the sprinkler.

This is exactly what phil lipton was saying a year or so ago, in multiple posts in this section. He also did some testing on it.
Its not the length of the blades but the pitch of the blades that increases the pull draw of air thru the radiator core.

At that time I also wrote about using 6 blade aluminum fan from DERALE PERFORMANCE , the blades are 4" wide and from the mounting hub in the middle pitch back 3/4". That's important for fan belt clearance.

The center hub would need to be fixed in a machinist vice and drilled or milled out to the size of your water pump mounting hub. The DERALE part number is 17513 for 13", 175 for 15", 175 for 17" , 175 for 18". They also make this fan in all steel but its heavy and most likely would wear out the hub packing quickly.

I have a similar fan from a late sixties Chrysler dart with 383 motor that was used with air con cars. At idle ....650--700 rpm , it will draw a cloth diaper to the grill and keep it there. Solved my overheating problem long time ago.

mike lynch " the real & original madmike3434"

that should be part number
17513 for 13"
17515 for 15"
17517 for 17"
17518 for 18"

mike

This is Phil Lipton; I'm the guy that wrote about the truck fan blade (in my '29 to '49 Parts book, in fine print where the truck fan blade is listed, it says (can be used for additional cooling) and fits passenger cars perfectly The car and truck engines and water pumps are the same! My '35 Std Coupe has the 207 C I engine that always ran hot, but never boiled over! I installed a NOS temp guage to keep an eye on it! Installed a nos '36 head (with improved cooling) and fit the '35 block perfectly. Installed a new water pump baffle plate, installed a new 'high efficiency' radiator core, but on a 90 deg. day, at idle temp was 190-200 deg. Truck fan blade now keeps temp about 20 deg. cooler under same conditions! Driving on a hot
day or in a Parade is no longer a 'nail biter!' I must warn
you, the truck blades are very difficult to find! I've been looking for them!

I have 2 extra fan blades. What do I look for to see if they are the truck blades?

After cleaning all of the rust and debris out of the block in my 34 Master I followed Phil's advice and installed a truck blade. Results were very good. Here is a link with a picture of the two blades. The truck blade is on the bottom. Hopefully the link works. Mike

https://photos.google.com/share/AF1...azh0OGg2anAtQkNBVlB5MjltSnpvVTJoUzVkcmNn

This will be long, so most of you may want to skip it. Your call.

Rust Buster,

There have been some good suggestions on what to do with your 36. Some better than others but all trying to give you good advice. I don't know much about using chemicals other than the solutions used in boiling radiators back in the day.

Having been a radiator man - following my father who was one much longer than I -, here is my suggestions: (All the following is absent your being to find a suitable and reliable radiator shop. And, some of what I'm going to suggest has already been mentioned by others)

a. Take the bottom hose loose at the pump.

b. Take the top hose off. Find something to divert pressurized water from going all over the engine and especially distributor.

c. Take the thermostat out. (more on the thermostat later)

d. Get a live garden hose for supplying water to the top of the radiator.

e. Get an air compressor with a nozzle that you can wrap a towel around and stick as tightly you can into the bottom radiator hose.

f. With a supply of water going in through the filler cap opening, flush the radiator. This will be in reverse direction the water flows through the engine. Keep doing this until the water runs clear or you think you have done about all you can. (Hint for how much you have achieved: Fill the radiator first with your hand over the bottom hose and then release and notice the height of the water as it is released when you take your hand off. Do this before and then afterwards.)

g. Take the petcock out of the left (driver's side) of the block. Probe with a wire and shoot air up through the block and clean it best you can.

I. Put the bottom hose back on and fill the radiator. With the thermostat out, trip the fan belt and crank the engine. This is a test for blown head gasket or cracked head or block. Water should sit still.

j. Clean the fins of the radiator of bugs and such so there is least restriction to air flowing through.

Here is some thoughts on chemicals:

a. If you are going to use one for cleaning. Do that first then the reverse flush stuff I mentioned above.

b. A lower rated thermostat will not cure overheating problems unless it is sticking in the closed position. Not likely. Your 160 degree on merely means that it will open at that temperature. It will not control the temperature above that rating.

c. Reverse flushing will merely flush out those flues sufficiently loose that the pressure can dislodge and/or as many as will accept the pressurized water you blow back through the radiator or block. Nothing more.

d. A suitable truck fan will offer some relief at idle and low vehicle speed. It is a help but not a solution.

e. If you can get the radiator rodded then do that. It entails getting the top tank off, boiling the tanks and core and with water flow, using strap steel to probe the individual flues. Not all flues may be freed up. Not to worry. Read on.

f. After the radiator is cleaned and rodded and the top tank back in place, it should be tested with about 10 lbs of pressure. An old core ill have leaks. They should be cleaned and soldered up. If some flues are rotten then they can be eliminated by cutting out and soldering up. About 10-15 percent can be eliminated without having to recore the radiator.

g. If during the test there are tiny bubbles noted, there is no need to chase them. Just use some engine builders graphite or Solder-Seal. These will take care of the minor holes in the core.

h, You need to be diligent in observing loose stuff from the block stopping up the reverse flushing or rodded radiator. Best to have dipped the block as well but that is a heap more trouble.

See if anyone has a new radiator or a core. Harrison is what you want. It will be a good investment. New aluminum radiators may suit. I'm not familiar with them and their cost and availability.

With the cooling system acting normally. I would put a 180 thermostat back in. You engine needs to run at that higher temperature than 160 degrees owing to efficient oil flow to the bearings. Too cold is not too good. Remember this is metal not flesh and bones.

If you have any questions, please let me know.

Best wishes for success,
Charlie