News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

Water pump pulley-1940 LaSalle Flat Head V-8

Started by CraigD, April 06, 2018, 10:20:14 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

CraigD

The outside diameter on the water pump pulley on my 1940 LaSalle model 52 is about 5". Can anyone tell me if that is the correct size? I am wondering if the water pump is spinning too fast and pumping more coolant than the radiator can take at higher speeds. That's why I am asking the question.

I am losing coolant through the overflow at higher speeds (50-55 MPH). I have replaced the radiator cap with the correct cap, even though the original cap was the correct depth and pressure and seemed that it was working properly. As far as I can tell, the cap is seating properly. I have replaced the water pump and the hose feeding it (since the hose was mushy). I have had the radiator re-cored. The original core was about 30% blocked. Re-coring it seems to have reduced the problem, but the problem is still there. I can't see any signs of exhaust getting into the coolant. I know that you can't fill the coolant up to the top â€" I fill it to about 1.5” down â€" but with high-speed use even after the re-core, the coolant has gotten down below the top of the coolant inlets and some is still coming out the overflow. In the past before the re-core, the level has gotten as low as the top of the core. BTW, before the re-core, I would lose about a gallon of coolant on a 55 mile 50-55 MPH trip, so it is not just a trickle.

Craig Duerling
Cambridge, MD
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

Steve Passmore

5" is about right. Did they replace the core with one of the same size??
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

CraigD

Yes, the core is the same size with, as far as I can tell, the same number and positioning of the tubes and fins.
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

47SixtySpecial

If you let the rad find it's natural level... which likely is lower than you think is correct, does the engine overheat? Every Cadillac flathead engine I have ever had, I just filled them about an inch below the filler cap and let them find the right level. No overheat problems for me.
Joe Mark

CraigD

I've never had it overheat. When the coolant gets low, the temp will go up some, but it tops out at about 180° in warm weather and 160° in cooler weather. I just recently put the re-cored radiator back in, so these temps were with the somewhat clogged radiator. Is about 3.5" below the collar that the radiator cap rests on a normal level?
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

Steve Passmore

Temps are within limits. Just do what Joe said. Fill up to 2" below the top and run it. Let it discharge whatever it needs to and if the temp stays there leave well alone.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

CraigD

I followed the advice given here and drove it several day waiting for the radiator to find its level. I hooked up a coolant reservoir to catch the excess. The level in the reservoir kept rising with each trip. On the last trip, I noticed the temp rising some, but still quite within "normal" levels. I let it cool off and checked the radiator level, and it is now down to the top of the core. Something is definitely wrong, but I don't know what to try next.

I don’t know if the problem is the cap not sealing tightly around the lip in the radiator neck, but I can’t see any problem with either the lip or the rubber seal and I have tried two different caps. Maybe the engine at high speeds is pumping coolant into the top of the radiator faster than it can get back through the radiator, but it seems that with a closed system, the pump would starve for water before it could fill up the top radiator tank. Maybe there is something else I am missing.
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

47SixtySpecial

#7
at the top edge of the fins has been normal in every flathead caddy engine I have owned. 6 so far. I only ever had cooling problems once with an old rad. Recoring it fixed it but it still ran where you are describing yours as being. If the temp is staying steady and within normal I think you are good.
Joe Mark

35-709

A coolant overflow bottle requires a more modern type of pressure cap that will allow coolant to be drawn back into the radiator as the engine cools.  If you are running the correct radiator cap for your car, a coolant overflow bottle is not going to work correctly.   As has been suggested, replenish the coolant about halfway up from the core and let it pee out what it doesn't want and then see if it doesn't maintain that level.
1935 Cadillac Sedan resto-mod "Big Red"
1973 Cadillac Caribou - Sold - but still in the family
1950 Jaguar Mark V Saloon resto-mod - Sold
1942 Cadillac 6269 - Sold
1968 Pontiac Bonneville Convertible - Sold
1950 Packard 2dr. Club Sedan
1935 Glenn Pray - Auburn Boattail Speedster, Gen. 2

CraigD

Thanks. I had understood that the coolant reservoir won't work with this type of radiator cap as far as sucking the coolant back into the radiator. I was primarily using it to tell how much coolant was coming out of the overflow and keeping it from running onto the ground.

I filled it about half way up, but while driving about 75 miles, it pushed out enough coolant so that the top of the radiator is almost empty. There is only about 1/4" of coolant left above the core. "47SixtySpecial" says that this is normal for his cars. The temp was running at about 140° on a day where it was about 55° ambient. (The thermostat doesn't work, so I have the shutters wired open.) When the coolant got down to this level, it was running at about 160° which is still not all that hot. I guess I'll drive it some more (with extra coolant in the trunk just in case) and see what happens.
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

47SixtySpecial

It's fine to have the coolant at that level. You are only getting actual cooling from the tubes and fins.. the reservoir up top does nothing to cool the engine. It all sounds as if working correctly to me.
Joe Mark

CraigD

1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

harvey b

Do you have the right cap on the radiator,some of these cars take a cap with a long neck on it?,not sure about your car but my 37 has a distinct style of cap.the distance from the seal to the bottom of the lid is the difference,hard to explain,but the seal doesnt touch the inside lip on the rad,at those temps the coolant shouldnt hardly expand and push out,it shouldnt build up enough pressure at that temp.might be something to look at. good luck   Harveyb
Harvey Bowness

CraigD

Thanks Harvey. Yes, the cap I have is correct for the deep neck on the radiator. I even bought another one just in case, but the results were the same. I understand that apparently it will run with the coolant level down to the top of the core, but that can't be the way it is supposed to run as the thermostat would no longer be be in the coolant and would probably close the louvers. That doesn't effect my car as my thermostat doesn't work, so I have the louvers wired open.

My guess as to what is happening is the the water pump is pushing coolant into the top of the radiator faster than it can go through causing a pressure build up in the top of the radiator. I have no way of proving that though.
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

z3skybolt

Appears to be normal,

I've driven my 40 LaSalle nearly 3,000 miles with coolant levels and temps as you describe.

Bob
1940 LaSalle 5227 Coupe(purchased May 2016)
1985 Lincoln Town Car Signature Series. Bought New.

CraigD

Thanks Bob. I had an episode last year before I understood what was happening and before the radiator was re-cored where the  temperature gauge (after market so I can tell exactly how hot it is running) was varying quite a bit - like 200° to 160° in less than a minute. I wasn't far from home, so when I got home, I let it cool off, opened the radiator cap, and couldn't see any coolant at all. I guess I am just paranoid now about the coolant possibly getting down that far again. I would feel a lot more comfortable driving it any distance if there were at least enough coolant that I couldn't see the top of the core on a regular basis. It sounds like some folks have that radiator level and as I said, it must have been that way originally for the thermostat to work properly.
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

47SixtySpecial

#16
I don't think those thermostats ever worked properly. It was a faulty design. My first caddy flathead was a one owner when I got it. I asked him a bunch of questions, including why the shutters had a hunk of wood jammed in them. He told me he had to block the shutters open right from the start.

I unhooked the thermostat and connected them to a choke cable so I could get some heat when driving in colder weather.
Joe Mark

CraigD

Thanks Joe. Great idea about hooking it up to a choke cable.
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

CraigD

Update: I drove the LaSalle for about a half hour yesterday on back roads at 40-50 MPH starting with the coolant in the radiator just over the top of the core as suggested it should work. Outdoor temp was about 75°. It started out at 140°. After a while, it rose to 160°, then 180°, then topped out at around 190°+. At 190° plus, each time I stopped and idled for 30 seconds or so, when I started back up and got it into 3rd gear, the engine started bucking - starving for fuel. I assume that this was vapor lock. I dropped it into 2nd gear to get the engine turning over faster and the fuel pump working faster, and that seemed to solve the problem. It never completely stalled. (I have an electric auxiliary pump that I intend to install this coming week to hopefully alleviate the vapor lock problem and make it easier to start after sitting for a few days.)

When I got back home, there was more coolant in the overflow tank indicating that it was still pushing coolant out of the overflow. The coolant level was down below the top of the core, and I am guessing that a lot of air was getting into the system causing it to not cool effectively. I have found through experimentation that driving back roads at 40-50 MPH seems to cause more overflow than just driving down the highway at a fairly constant speed. I am guessing that each time you accelerate, a surge of coolant goes into the upper tank causing it to overflow. I may be completely wrong.

It seems that my car's cooling system is just not working like others on the forum. An ideas of how to diagnose and fix the problem would be greatly appreciated.

Craig Duerling
Cambridge, Maryland
1940 LaSalle Model 52 Special
2007 BMW 530i
2015 Jeep Grand Cherokee Limited

Bill Ingler #7799

Craig: Does the bottom hose from the water pump to the radiator contain a spring? The purpose of that spring is to prevent the hose from being partially sucked closed by the pulling action of the pump. The faster the car goes, the faster the pump turns and then the slower the water moves through the radiator.    Bill