1939 buick special radiator removal procedure

hi first I am brand new here. own a collision shop and picked up a 39 buick special 4 dr at an estate sale a year ago.

I have it sorted out and daily drive it. now im suspecting a blocked radiator. as it creeps hot and never goes down.

I need to know if it is true to . remove water pump and blade. that this radiator can sneak out..as in hood off and radiator straight up is this fact? thanks and look forward to hanging out here. pics coming soon. thank you .

pops out of 3rd on deceleration.

one issue at a time.

you probably need the detent springs for the transmission, Bob's Automobilia sells them, they commonly are missing after years of use

Popping out of high usually means a bad bearing on the input shaft or someone left the spring washer that goes against the input bearing out (common) on the last clutch job

Hi.is the radiator removable from pulling hood fan blade and water pump? Without removal of complete nose

Yes, the '38-'39 shop manuals say radiator can be taken out by removing the top hood section, fan, water pump and screws holding core in anchor band.

Hi. Thanks radiator is out. Ok by pass valve block is empty.is it ok to seal off with a freeze plug? Or fine without anything in it. I need to figure how to attatch pics to thread.. im sure thinking radiator is blocked. I had a temp reading at fill neck of 210 degree. And was able to put my hand on lower and was barely warm... thanks for helping...

Was the thermostat there but the by-pass missing? There have been some on the Forum who say the by-pass is not needed if you live in a warm climate or insert a plug with a half inch hole in it. Some even say the thermostat isn't necessary in warm zones. I have both in my '39, and I am in Texas where it rarely gets into the teens. You might check to see if you're getting any flow through the rad by flushing it with a hose. Also might check the lower hose to be sure it isn't collapsing and preventing the water from returning to the engine - this would make the lower radiator cooler than the top tank and also overheat the engine. There is usually a wire coil inserted in the lower hose to prevent it collapsing.

If the blockage isn't in the radiator I would think flushing the engine is your next step. There is a drain cock on the lower block below the distributor. If you take it out and run a coat hanger wire into the water jacket while flushing, you may get enough junk out to solve the problem, if not you can use a piece of copper tubing with the tip flattened out a bit on the end with a pressure washer to snake around in the water jacket to loosen things up. Next step would be to pull the freeze plugs and flush there with the pressure washer.

There have been several conversations on the Forum about what people have used for flushing to resolve overheating issues, so if you use the Search function you should locate some good advice.

Hope the radiator is the problem as that is the easy fix.

Here is one of the Forum posts about flushing the system: http://forums.aaca.org/showthread.php?t=327886

Welcome to the world of '39 Buicks. You can join the '39 Buick team here on the forum/

Removing the complete front end sheet metal is easy. The '39 Buick thread has a link to a thread describing how it’s done/

As for the transmission, as well as the good information in post 2 & 3, check the engine mounts & torque tube rubber joints behind the transmission are in good condition.

Straight 8's are notorious for having rubbish & sand in block particularly at the last cylinders.

The easy thing to do is remove the front sheet metal, radiator and all. Two man lift job. Take off the hood. Take loose the fender braces and a big bolt on the bottom of the radiator. I have forgotten the count, but there are about six bolts on either side, holding the rear of the front fender to the cowl. There is one bolt that holds the side panel to the firewall. You also, of course have to disconnect the radiator and heater hoses, empty the radiator. Then pick the front end up, lifting high and walk away with it. A third man in the front will help you walk away with it. Also, the thermostat bypass has a valve in it that often seizes or doesn't work. You can either repair or replace the thermostat housing, or take out the valve, or install a 1948-49 thermostat housing that does not have the valve. I don't know where popping out of third gear came into the conversation, but that is usually caused by a work out 2nd & 3rd shifting fork in the transmission. That is what I've learned in 69 years of collecting 1939 Buicks and other pre-1950 straight 8's with the small engine.

Thank you all so much.here is my tests so far to date. The radiator came out easily from top removing waterpump and fan assembly.and goooseneck and housing. I found a 195 thermostat not correct for car. And found wide open hole where valve should be.since im suspecting blocked (2nd core by the way).i can see its been recored. Well i installed a dumby radiator from a 70 nova 396. Sideways in there for a test. It also creeped up to hot driving around my neighborhood. Next i installed restrictor plate with small 5/16 hole.in the bypass hose.i removed the 195 thermostat. Boy it runs one dot

over medium. I wonder now if the stock radiator is ok.so sending stock radiator to just get chked. .question please.can a radiator shop boil to get crap out of it.thank you thank you.

What does that coolant valve do

Hi. Again thank you guys so much. I got a manual today 38.and suplement to 39.this water valve is for recirculation. Actually says.NO water will go threw the radiator at all when in recirculation mode. I had no idea.. so my restrictor of 5/16 hole.and No Thermostat may be my fix

It is very important to have that bypass valve in the housing as the water will not circulate through the radiator with out it !!

The bypass valve, when the engine is cold and the thermostat is closed, allows the water in the block to recirculate to warm the engine up as quickly as possible.

When the thermostat opens, the bypass valve closes and directs the water flow through to the radiator to be cooled.

The alternative (if you can't get a hold of the correct pieces) is to fit a permanently affixed plate with a hole in it.

This is what they did with the later models (1/2" I think) and did away with the bypass altogether.

As for boiling the radiator, that will usually only help a little.

It is best to get the top tank removed and definitely have the tubes rodded to be sure that there is no "gunk" left in them.

I'd also put the thermostat back in as it is far better for the engine to be running at the correct, stable and constant temperature.

Danny

They had that by-pass valve in the thermostat housing from 1934-1947. Sure took them a long time to figure out they didn't need it and change to the simple orifice in 1948. Although I never found this to be the problem in any of my cars, other people have, so I put on a new one or rebuilt the old one whenever I had to get into the water pump or thermostat. Always keep 3-4 spare thermostat housings on the shelf. The 1948-1949 bypass is completely interchangeable with all '39 models. Although the water pump was different between the large and small engine and the water pump was change in 1941 and kept the same through 1949, the thermostat housing only changed in that they eventually removed the valve.

You folks are awsome.im so glad your all so nice and so smart.