Coolant level

[greaser13]

I have a very temperamental 50 Plymouth, if her coolant doesn't sit between a 1/2 inch to 1 inch below the filler neck she wont run right. But they never came with an over flow res... so she needs to be watched. Does anybody know why? 

 

[knuckleharley]

What do you mean by "won't run right"? What is it doing? Is the engine cold or hot when it does this?

[desoto1939]

More information is need as to what you mean by not running right.  Is the temp on the temp gauge getting to the max or what.  Might need to hav ethe radiator cleaned and rodded and oreve the engine block flushed or a new water distribution tube.  Is you water pump leaking do you have a thermostat installed in the block?

 

Is the thermostat clogged or closed or broken.

 

rich Hartung

[mopar_earl]

I added a coolant recovery tank to my 52. The rad cap needs to be coolant recovery tank compatible so it will draw the coolant back in as it cools down.

Earl

[knuckleharley]

I added a coolant recovery tank to my 52. The rad cap needs to be coolant recovery tank compatible so it will draw the coolant back in as it cools down.

Earl

Since you need to use a cap around the 4lb pressure rating area,can you tell us the parts number and make for the cap you use?

[mopar_earl]

I couldn't find a 4 psi cap with coolant recovery compatibility. I ended up with a 7 psi cap from Napa. The Napa cap number is 703-1460. The coolant reservoir Napa number is 730-4514. I used these with the Champion aluminum radiator. The cap would fit my original radiator. This is on a 1952 Dodge.

Earl

[greg g]

Afew years ago I went to a car show.  The space next to me was filled by a fellow with a very nice 40 Desoto.  As soon as he pulled in he opened the hood and was bemoaning the fact that his radiator was spitting out antifreeze.  I asked him if it was somethingnew and hesaid it happened every time he drove the car.  I took a look at the temp gauge and it was just the 180 mark.  He went and took his registration papers to the club tent, and thencame back to the car,opened the trunk brought out a gallon of coolant.  When the radiatorcap cooledoff he opend it and peered in.  He mumbled about something and started to add the coolant.  I questioned as to why he was adding coolant and said it was low again.  Looking in I noted that the level of coolant int he radiator was over the top of the core by about 3/4 of an inch.  

 

At this point I decided to ask him how much he was going to add.  He said he was going to fill it up as he always did.  This is when I reminded him that as designed his car was a 0 pressur system and the space at the topof the radiator was by design the expansion area forwhen the fluid got hot and expanded.  I said to leave it where it was, and to drive home keeping a close eye on the temp gauge.  I assured him that all would be well and that the procedure he was using made sure that ithe system would overflow when hot.  He looked skeptical but put his coolant jug back inthe trunk.   I saw him later in the summer at another show and asked him about his radiator problems.  He told me that he had not experienced any further overflow problems, the car hardly ever went above 170 to 180 degrees, and he was a happy camper.

 

The system needs to find its own operating level.  Adding more coolant just because it "seems" low is a self defeating process.  Cover your core, check your temps as you operate your car.  If you have doubts about the accuracy of your gauge, check it via another source.  

 

How coolant level can effect the way a car runs is a question I can not understand, unless it it overheating so badly, and so hot that it missfires due to pre ignition. or looses power from beginning to seize.   

 

REally would like to hear back fromthe original poster as to what his exact symptoms are.

[knuckleharley]

I couldn't find a 4 psi cap with coolant recovery compatibility. I ended up with a 7 psi cap from Napa. The Napa cap number is 703-1460. The coolant reservoir Napa number is 730-4514. I used these with the Champion aluminum radiator. The cap would fit my original radiator. This is on a 1952 Dodge.

Earl

 

I'm sure you are safe with the new radiator,even if it were the original design. I'm not so sure about a 7 psi cap on an original radiator that has been heating and cooling for 65 years,though. Since a new Repo radiator for my 51 is $590,I am hoping I can get by for one more summer using my 4 psi cap and checking the water after every drive. It's going in my shop late this summer for a tear down for new floors,patch panels,paint,glass,and wiring anyhow,so I won't be needing a new radiator for it for a while once it goes in by shop. Until then I plan on driving it locally every day it isn't raining.

[knuckleharley]

The system needs to find its own operating level.  Adding more coolant just because it "seems" low is a self defeating process.  Cover your core, check your temps as you operate your car.  If you have doubts about the accuracy of your gauge, check it via another source.  

 

The gauge in my 51 wants to hover between warm and hot (dashes,not numbers) when driving it in the summer. Since I don't have numbers to look at and am unsure about the reliability of the original temp gauge,I bought one of those digital temperature "guns" from Amazon for $14. It shoots a laser beam at any object you point it at,and gives you a digital read out that is pretty damn accurate. You can even use it to check to see if any one cylinder is running hot. For 14 bucks I figured it was worth buying to keep a check on my radiator temps,rear end temps,tire temps,bearing temps,etc,etc,etc.

http://www.amazon.com/Etekcity-Lasergrip-1080-Non-contact-Thermometer/dp/B00DMI632G

[mopar_earl]

I'm sure you are safe with the new radiator,even if it were the original design. I'm not so sure about a 7 psi cap on an original radiator that has been heating and cooling for 65 years,though. Since a new Repo radiator for my 51 is $590,I am hoping I can get by for one more summer using my 4 psi cap and checking the water after every drive. It's going in my shop late this summer for a tear down for new floors,patch panels,paint,glass,and wiring anyhow,so I won't be needing a new radiator for it for a while once it goes in by shop. Until then I plan on driving it locally every day it isn't raining.

You can buy a Champion aluminum radiator 3 row core much much cheaper than $590.00. Unless you have to have an original looking radiator. Love the Champion radiator I put in my 52. My original radiator core was beyond repair, and they wanted about $500.00 to recore it. I spent $200.00 or so if I recall for the Champion.

Earl

[knuckleharley]

You can buy a Champion aluminum radiator 3 row core much much cheaper than $590.00. Unless you have to have an original looking radiator. Love the Champion radiator I put in my 52. My original radiator core was beyond repair, and they wanted about $500.00 to recore it. I spent $200.00 or so if I recall for the Champion.

Earl

Thanks for the tip,but I am going to spend a ton of money putting this thing back together as close to factory original with paint and upholstery and the original drivetrain,so I guess I will just have to bite the bullet and pay big bucks for a repop radiator. If I don't,it will be like a poke in the eye with a stick every time I raise the hood. This and my 31 Plymouth coupe are cars that are going to remain original.

 

The 51 will have modern radial tires,2 carbs,split exhaust with glasspacks,and 50 taillights,but nothing that can't easily and cheaply be changed back to original. The 31 is getting nothing changed.

[greaser13]

Sorry, i have been out of town and back, finally got to log in. So, the 50 Plymouth is overheating. I'm thinking it may be timing, had to rebuild the dizzy and put it back in. She starts but wont drive any where, still trying to figure this car out all the way. My last car had a 401 Nail head and that was more familiar than this flathead but, I wanted a challange

Edited May 25, 2016 by greaser13

[TodFitch]

Do you have a service manual? These beasts are pretty basic, but the manual will get you on the right track as far as tune up specifications, etc.

[Worden18]

Stant makes a 4lb. cap, part # 10208.  I recently went through the whole radiator debacle with my 51 Meadowbrook.  I thought the radiator was leaking; antifreeze was spraying onto the engine.  The radiator was about as green as the Statue of Liberty.  I took it out along with the heater core and had them pressure tested.  The radiator shop did so; a 7lb. test.  No leaks.  He concluded the antifreeze was spraying out of the cap, which was completely shot (I should've known).  While the radiator and heater core were getting fixed I flushed the block the best I could.  Lots of crud and rust came out, but it wasn't as bad as I thought it would be.

 

 He boiled out the radiator and heater core and painted them for $60.  The old thermostat was stuck open (car was running much cooler than 180 degrees).  I got the whole thing back together and once the system was running at the proper pressure the water pump blew.  What a damn fool I was not changing it when I had it all apart.  So everything came back out.  New water pump installed.  Everything back in (including new hoses, etc).  NEW WATER PUMP LEAKED out of one of the screws on the backing plate.  Everything back out again.  Removed the screw, siliconed it up, then everything back in again.  No leaks.  Filled it with coolant about an inch or two from the top, car runs 180 degrees whether I'm driving 40mph or 65mph.  I have no overflow reservoir.  Everything works as it should.  

 

Guess I just wanted to tell my story.  Biggest thing I wanted to share was that Stant makes a 4lb. cap, and that if your radiator is flushed (or new, repaired etc) and you have a new thermostat and water pump your engine should do just fine.

[mopar_earl]

My new water pump leaks out the cover plate bolts too. I pulled all but one that I can't get out due to location and used thread sealant. On my list to pull the pump and seal that last bolt. Pump was a new Napa pump. Apparently the bolts go into the cavity and they didn't seal the bolts.

Earl

[Don Coatney]

I think many of us have had that leaking problem until we learned to seal all water pump bolts.