Lasalle radiator cap

[tturley]

I have a 40 lasalle and when I bought it Someone had removed the works from the radiator cap. Any idea why? Replaced with right 7 lb AC but runs pretty hoy.


The car came from Maryland and has a Maltese cross painted on the front doors, any idea about that?

[camelot]

I just put a brand new 3 row copper radiator core with my original tanks in my 40 Lasalle. I checked the shutterstat for operation and it seemed to open wide in 170 degree water. Probably would open partially at a lower temp. The other day I put about 25 miles on it on secondary roads and it would hit just shy of 3/4. just past 1/2 on the guage. Temp that day was in the 80's.  I also drove it on the interstate here ( maybe 50-55)  for about 6 miles and it stayed right about 1/2+ guage. Again temps in the 80's Its not steaming over but did burp out about a cup full of antifreeze when I shut it off. I keep the tank at 3/4 or just above the upper radiator hose outlets. I also have a 7lb cap on it from Napa. Not too worried about it right now.  I've got about 70 miles on the car since I got it  2 mos. ago. And it's the first time its burped anything out.

[tturley]

Have you checked temp with infrared thermo? Mine is running about 3/4 on gage and infrared says 210 at front of head and 220 at back

[Jim Stamper]

     Have you checked the depth of the radiator cap into the neck of the radiator?  The necks of radiators in LaSalle radiators, and others, are a bit deeper than in later years. Yours may not be sealing by much, so it is not getting 7 # pressure.  Just a thought, that situation is not uncommon wit the incorrect caps.  Jim Stamper CLC#13470

[tturley]

I will check that.
Thank you

[Bill Ingler #7799]

To add too what Jim has said about sealing using the correct length cap. Attached is a chart showing the correct A/C cap for several makes of cars. You will also find a drawing showing the cap depth must be 1/4 inch more than the depth of the radiator neck to insure a good seal.  Bill
 

[tturley]

Thanks
I will check that

[Alan Harris CLC#1513]

These fellows are right about the depth of the radiator caps being important. It is also important to note that the owners' manual states that it would not be a cause for concern if the gauge goes all the way to "H" after a hard drive on a hot day as long as it does not remain there for an extended period. It also says that if the car is not boiling, it is not overheating.

My 40 LaSalle runs at about halfway up on a hot day, but will go as high as 3/4 on a long uphill pull.

When I first got the car, the radiator would burp up a bit of coolant when hot. I soon learned that the car would do that as long as I kept topping it up. When I let the system find its own level, it has been fine since.

[tturley]

I checked and I do have the correct cap.

Glad to hear that the gage reading on the hot side is ok. It does not boil over and seems to start when hot so I will try to ignore the gage.