440 Heat Sinking (boiling over after shutdown) revisited

[class87]

From: SmallDiscoveries1  (Original Message)
Sent: 7/6/2006 12:39 PM

I know this has been discussed before. I just wanted to discuss it again, because I don't see a definitive answer for my situation.

My 440-3 will run at a low temperature, at least according to the guage, while driving down the road and even extensive idling after being driven for a while. When I shut it off, it heat sinks and boils over. The problem is, it doesn't seem to be going into the tube and down to the bottle. The bottle has a low and high setting on it, but just a plastic cap. Should it actually dump into there and then suck it back up as it cools down?

The coolant runs out of the cap on the radiator and onto the ground. What are the correct pressure caps to have on the radiator and extension?

If it isn't one thing, ie. not starting when warm, its another.

Thanks guys, and gals.

Steve



From: SmallDiscoveries1
Sent: 7/6/2006 12:43 PM

Crud! I should clarify. It is a 74 with a thermoquad. I have a newly rebuilt radiator. The engine has been flushed. I have two auxilliary transmission coolers, mounted low on the grill. It has a new, correct skirted thermostat. It has all new hoses. It has a new water pump. It has 50/50 concentration of the orange stuff and H2O. The timing has been set. It could be running lean due to needing a carb rebuild. It doesn't miss or show a vacuum leak though.

Did I miss anything? Is this normal?



From: denisondc
Sent: 7/6/2006 2:48 PM

If yours came with an overflow bottle, the way it should work is that the fluid will be drawn from the bottle back into the radiator, as the engine cools for a few hours. In use the coolant expands, and the extra goes into the overflow bottle. I would expect some small amount of further expansion after the engine is shut down - but i would expect it to be so slight that you would not notice it.
So... you water temperature might be too high, but your gauge might be reading low. The sender is not expensive, and I had to replace mine twice in the time we have had our Winnie. You might simply have a bad radiator cap. The 440s used a 16 psi cap, but whether it was the type that always kept pressure, or the type that didnt seal off until water sprayed against it, I dont know.
Its possible the overflow rubber tube has a leak, so water isnt pulled back into the radiator overnight as things cool. This results in an air bubble at the top of the radiator, but shouldnt cause boiling over - unless the air bubble gets very large. This amounts to low coolant level in the radiator.



From: Cooneytoones
Sent: 7/6/2006 11:37 PM

SD....
Mind does the same thing as yours, I loose about 3 or 4 oz's or so and I have been looking for the cause for a year now...I have a '76, same 440-3 with a new rebuilt TQ....new overflow line to the bottle, but it seems to come out from around the cap when I shut it down after running at any lenght of time.....even if I idle it down....I have a 16lb pressure cap on it now...and not found the soulution except...I just add some mix to the bottle and that seems to keep the radiator full.

Lookin'fortheleaktimmy



From: DaveVa78Chieftain
Sent: 7/7/2006 1:01 PM

Well, ahh, the stock 440-3 Dodge radiator has 2 radiator caps.  1 on top of the radiator and 1 on the fill extension tube.  The overflow hose goes to the one on top of the radiator.  Are both caps ok?  If yes, then it's either:
1.  A crack in the brass overflow tube outlet or,
2.  A hole in the hose or,
3.  A hole in the overflow tank or,
4.  Pinhole leak in radiator or,
5.  Leaking head gasget

You may have a pressure drop down test performed to find the culprit.

Dave 



From: SmallDiscoveries1
Sent: 7/7/2006 2:26 PM

I bought two new caps last night. For the life of me, I could not get the one back onto the radiator. I even tried to move the cap that had been on the extension to the radiator and could not get it to seat. That is, I couldn't push any of them far enough down to get over the ridge on the neck. I'm thinking hitting it with a dremel may be in order. That ridge is just too tall.

I'll try it again today in the light.

It did appear the cap that was on the radiator was old, but the one on the extension was fairly new.



From: tatkin
Sent: 7/7/2006 4:46 PM

I thought I remember reading somewhere around here that it is good practice to let the engine idle for 5 minutes when ending a trip.  To let the fan cool the engine down a bit.   On new vehicles they have those fans that keep running after you shut off the engine ...



From: tatkin
Sent: 7/7/2006 5:08 PM

This is from the Motor Home Chassis Service Manual 1976

All vehicles are equipped with a "coolant reserve system " to allow expansion of heated coolant from the radiator without loss from the system.  Expanding coolant is allowed to flow through a hose into the reserve tank, then drawn back into radiator as the cooling system temperature decreases, heeping the radiator full at all times.  A special radiator pressure cap rated at 16 psi is used with the coolant reserve system.

Coolant level is checked by observing the level in the plastic reserve tank, not by removing the radiator cap.  Level should be between the two marks indicated on the bottle with engine cold; at normal operating temperature (and above), the coolant will be above the two marks as much as two quarts.

When required, coolant should be added to the system only at the reserve tank.  Not by removing the radiator cap.  When adding coolant, use only a 50/50 mix of permanent-type anti-freeze and water.

Testing coolant reserve system.

With coolant in the reserve tank at the proper level and radiator cap installed, open the radiator drain cock.  Coolant should be drawn from the reserve tank into the radiator.  If test does not draw coolant fron the reserive tank, check for leaks at the radiator filler extension and overflow nipple, radiato cap and reserve tank tube.



From: ClydesdaleKevin
Sent: 7/8/2006 12:22 PM

Even with a recored radiator, two new 7psi radiator caps (yes, 2 caps, on on the filler extention, and one on the top of the radiator where you can't reach it), a new overflow bottle and new hoses, my radiator does the exact same thing...I lose about a quart of fluid when I drive the Ark.  It doesn't matter if I drive it a 100 miles or a 1000, it loses the same amount of fluid...it just disappears...doesn't seem to leak out anywhere either.

The bottle keeps the same amount of fluid in it, but the radiator level drops.

I'm guessing that both outlets for the overflow hoses from both radiator caps are clogged/blocked.  I'll check it someday...lol.

Kev



From: SmallDiscoveries1
Sent: 7/8/2006 9:49 PM

In the daylight, I realized I was turning the cap the wrong way. Go ahead someone call me an idiot. Any of the caps go on just fine when you turn them clockwise. I bought some more coolant tonight, so tomorrow I will top off the radiator and fill the reserve tank. Well, not fill it but rather fill it to the cool setting.. I'll then observe it and see if it needs a new tank.



From: tatkin
Sent: 7/12/2006 10:33 PM

Water Wetter.  I had to check this out  ! A dude I somewhat know drag races. another dude I know is a stock car driver.    They both actually told me putting SOAP ! in the radiator makes the water travel faster and so keeps that water cooler ...   Water Wetter is a product.   Both of these people also told me to put pepper in the radiator to stop radiator leaks ...   I am typing this before research, but from the little I have done, they both appear to have truth ...  Chinese RV medicine ... 



From: jbmhotmail
Sent: 7/13/2006 12:59 AM

I have never heard of soap or pepper, however GM has an item called "Cooling System Seal Tabs", p/n 3634621, 6 tabs per package, tab size: 1" X 3/4", on the back of the package it states: Contains: Ginger, Almond Shell, Turmeric - CAS 458-37-7, Sal Soda. I have the original package with 5 of 6 tabs.
Jerry
85 Winnabego Chieftain 22
454, TH400, P30 chassis



From: denisondc
Sent: 7/13/2006 7:50 AM

Aside from the boiling, do you have to add coolant? Is that thermostat a 195 or a 180? I use a 160f thermostat in mine, since my driving is essentially all in hot weather. Any of the 3 temperature range 'stats should work, but the 160 gives you a little more slack before boiling.
You mention the orange stuff - I dont know what that is. I have used a 50/50 mixture, but now am using a 20% antifreeze 80% water mix. Water transfers heat better than ethylene glycol. Water also doesnt expand as much. If I were going to use mine in temperatures below 20f I would use a 50/50 mixture - or if I had a boiling point problem.
I have had trouble getting the radiator caps pushed down far enough over the first part of the neck to turn, even if I was able to be at a good angle above it.
All of the remedies may help, but a 440 should not use coolant at all from year to year; or something is still wrong.
You could have some remote corner of the engines water jacket where there is a buildup of crud, causing steaming when the water flow stops. Not feasible to fix except when the engine is rebuilt - by getting the block/heads boiled out or bead blasted with the core plugs out. This is all too common on prewar antique cars with large displacement engines.
If I had this persistent problem, I might take the distributor off and have its centrifugal advance curve checked.



From: Easybago
Sent: 7/14/2006 8:54 AM

I'm surprised no one has mentioned Engine Ice. I've been using this in my ATV's for summer riding for several years now. This product is kind of pricy, but it does yeild very good results. The following is a link to their site.

http://www.engineice.cc/products.html



From: SmallDiscoveries1
Sent: 7/18/2006 3:22 PM

The orange stuff I referred to, as opposed to the green stuff, is DexCool. The bottle shows that it has a higher boiling temperature when mixed at 70/30. So, I bought a new gallon and am adding at that ratio when it boils over. The culprit seems to be the barbed tube off the neck. I found that I could only fit a thin piece of cardboard about a quarter of an inch under it. It appears there was a repair made there at one time, maybe when the radiator was recored, and the solder is too thick not allowing a hose to fit completely onto the tube. It may have been a stupid maneuver but I took a hacksaw blade and cut into the solder to try to make room for the hose and clamp.

What else could I do? So I put the hose back on and clamped it down, but have not had a chance to test it yet.

The good news is, the generator seems to be running again. I had a kink in the supply line and ended up putting an elbow back on at the pump to prevent the kink. About $10 for all new brass fittings is what it cost me.

Steve