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Hi All,
I am happy to say I am enjoying short runs in this stunning car ( which draws much praise here in the UK) but over heating and excess play in the steering are a concern and will need to be dealt with this winter. Can anyone advise as where the water thermostat is located as this could be stuck and a likely cause for the overheating. Also I would appreciate any info on dismantling the steering box and replacement of the sector bush which appears to be the problem with the steering.
Many thanks, Peter
Hi Peter, I too have a '29 roadster with overheating problems. The thermostat is located in or on top of head where outlet for coolant is. The hose is attached to the outlet. I don't have a thermostat in mine and it still overheats. I have an excessive amount of rust in the block that I have been trying to get out. The water pump is working properly but I may need to re-core the radiator. I don't believe the radiator can be rodded out because of the honeycomb configuration. So; I feel your pain and let me know of any progress.
I'm lucky to have no steering problems. Fred
Hi Fred, it is good of you to reply but sorry to learn that your '29 suffers the same problem. I took off the thermostat housing from the block and also found that it lacked a thermostat. When I say "overheats" , I in fact mean that water spills out over the rad overflow as it heats. I note that the radiator cap is flat chrome with a rubber seal but no spring loaded seal as on the later models. Do you think this is the correct rad cap for this model? (With the overflow facility in place I do not understand how water is retained in the system as it heats and pressure builds).
I agree that the rad also likely needs back washing with a strong commercial specialist product....can you or anyone else in the club recommend the correct procedure and product?
Regards and best wishes for sorting this prob. Peter
Hi Peter, The system is not pressurized. Later on the systems became pressurized. I'm not sure just when that happened. So, the cap does not need to be air tight. There are radiator shops here in the States that will work on classic radiators but do not know if there are in UK. Good luck, Fred
Hi Fred, once again thanks for the helpful reply. It is good to get this confirmed. Have replaced the thermo housing and it is running again but will need to back flush the rad this winter when I am working on the steering sector bush. I will let you know how I get on with the rad/ cooling as and when. All the very best to you and all Desoto enthusiasts. Regards, Peter
Hello Fred and fellow twentyniners. Still not sorted the "overheating" boiling over problem. Now I am thinking that the absence of a thermostat may be causing excessive water pump flow which blows the coolant out of the overflow. So need to first try refitting a missing thermostat. Can anyone advise a current commercially available thermostat that will fit this car? If this does not work I will take out one of the easily accessible core (freeze) plugs and investigate build up of deposits in the engine coolant jacket.
Any further advice would be a great help to both Fred in US and myself in the UK!
Peter
Hi Peter, I too have come to the conclusion that I may need some restriction in the coolant flow to have it retained in the radiator longer. As soon as it warms up around here (I live in Minnesota) I will take a power washer and try to back flush the block and place a thermostat that has the center removed. Some "car guys" have stated that even a large washer put in would help restrict the flow somewhat. Keep in touch.
I found my '36 Airflow to run rather warm also. There's a radiator specialist near me, and I had him "boil out" the radiator and solder or braise up some tank leaks. I put in a new thermostat, and also had him back flush the motor once the radiator was back in the car. I had tried to do this myself with a commercial flush, but he got a lot more crud out with his specialist products and equipment. As for overflow, he instructed me not to fill the radiator so full. Leave a good two inches of airspace below the filler. That helped.
I think there is still a good deal of crud in the block that could be removed while the engine is torn down for a rebuild. But I'm hoping not to have to do that.
John Boyd
San Diego, California
Member National Desoto Club and Airflow Club of America
drjohn96@me.com
1936 S2 Airflow sedan (1)
1937 Chrysler Airflow sedan (2)
Dear John and Fred,
Very good of you to reply. I have now chosen an unused socket with a half inch drive hole and fitted it snugly into the 1&1/4" internal dia. top hose. Secured in place with a jubilee clip this should nicely restrict the return to rad. I will try this first before I start to investigate corrosion build up by removing a core(freeze) plug and water pump. Wish me luck and I will report back to you soon!
Hope you sort out any remaining challenges and happy motoring in great cars.
Peter
Here is a procedure for cleaning the passages of your cooling system without dismantling everything. This came from an old-timer mechanic from the Advanced-Design Chevy Truck crowd.
We've done it on a project and were pleased with the results. As a matter of fact, it cleaned the corrosion out of the radiator well enough that it opened some weak spots that we didn't know about.
It's supposed to be fun!
1949 De Soto Custom Convertible (project)
Many thanks Tim, I will certainly try this out before I start a gradual dismantling process to find and clear out any corrosion sludge. I will not be able to do this for a few weeks yet but will report back with results.
BW Peter
Awesome! I'll be anxious to hear what you thought of it.
It's supposed to be fun!
1949 De Soto Custom Convertible (project)
Hi Peter and others,
I can report success in the over heating issue of my '29. I just took an old thermostat and removed the internals and placed a washer with a 1/2 inch hole inside the remaining part of thermostat. Evidently, the water pump moved the coolant too fast through the radiator and it only needed some restriction in the flow. I always thought that without a thermostat the engine would be running as cool as possible. I was in error.
I have a 32 SC; I am having problems with it losing power and sputtering after a long (20-30 minute) run. Don't believe its electrical (everything replaced one at a time with no change in symptoms). No sign of a fuel problem. I began to suspect a vacuum leak that only shows up when engine is hot. I replaced packing on water pump shaft as it had started to leak more than before. Ran for 20 minutes under load with no issue. I would like to confirm water pump is working correctly. Is there an easy way to do this? I plan to double check the temp gauge to see if the 160F reading on the dash is real. That's where it runs when warmed up. Any other ideas or suggestions welcomed..
I have a 32 SC; I am having problems with it losing power and sputtering after a long (20-30 minute) run. Don't believe its electrical (everything replaced one at a time with no change in symptoms). No sign of a fuel problem. I began to suspect a vacuum leak that only shows up when engine is hot. I replaced packing on water pump shaft as it had started to leak more than before. Ran for 20 minutes under load with no issue. I would like to confirm water pump is working correctly. Is there an easy way to do this? I plan to double check the temp gauge to see if the 160F reading on the dash is real. That's where it runs when warmed up. Any other ideas or suggestions welcomed..
Suspect bad condenser or coil. Condenser is cheap so change that first.
Good Luck
Steve
