Overheating!! Time for a Rad flush

[soth122003]

TimFX,

I found that using a CLR product after the first flush will clean out the engine and rad pretty well.  Your P-15 with a heater holds 3 gallons. Use one gallon of CLR two gallons fresh water. Fill and run the engine until warm, let it set about 1/2 an hour then drain and flush with fresh water again. When you drain the system remove the petcocks and watch for the big chunks and use a pick on them. The CLR is pretty mild as long as you don't let it set in there for a long time. That being said, once you do this, keep an eye out for pinhole leaks. Sometimes when the rust comes out it will uncover a pinhole. Once you finish the flush, I would pull the rad an flip it over and flush from the bottom to the top. Helps get rid of the crap that came into the rad thru the t-stat and cant pass thru the cooling fins of the rad.

I did this on my P-15 and it runs at a constant 170 with a 160 thermostat in it. As far as the T-stat goes if you live south of the Mason Dixon line use a 160. North use the 180.

Joe

[TimFX]

14 hours ago, keithb7 said:

Yes thats it. Just twist it until the coolant flows out. No need to try and remove the drain assembly completely. 

Nothing came out. Wasn't plugged with crud. Had engine oil on it so I suspect this is not the coolant plug. 

[keithb7]

Uh oh. Something is up. Thats the block coolant drain in the pic. There's no oil in there. Unless oil is entering the cooling system. Got any pics of the brown crud you found when you removed your rad cap? Is it possibly oil mixed in with the coolant? 

[TimFX]

16 hours ago, keithb7 said:

Yes thats it. Just twist it until the coolant flows out. No need to try and remove the drain assembly completely. 

Edited August 6, 2017 by TimFX

[Young Ed]

1 hour ago, keithb7 said:

Uh oh. Something is up. Thats the block coolant drain in the pic. There's no oil in there. Unless oil is entering the cooling system. Got any pics of the brown crud you found when you removed your rad cap? Is it possibly oil mixed in with the coolant? 

There is an oil gallery plug in that one too. For the posters sake I'm hoping he just pulled the wrong one!

[TimFX]

My parts list book doesn't list it. 

'Does anyone have the  service manual with a picture or diagram?

[Frank Elder]

 It could be your block needs flushed to get rid of blockage. as in torn down and tanked.

 

Edited August 7, 2017 by Frank Elder

[Don Coatney]

Number 5 in the photo below is pointing to a plug in the oil galley. Top left corner of the number 5 post it is touching the water jacket pet cock used to drain the engine block.

[55 Fargo]

Okay are we "chasing our tails" on this thread.

I mentioned above or possible  another thread on "overheating".

Pull the rad, send it out for boiling and clean up, its a honeycomb rad? if so no rodding is possible..

Pull the water waterpump, and remove the water distribution tube, clean and verify its in good condition.

Next pop open the lower welch plugs, rod these areas out of crud, flush frontwards and backwards, this should clean up the engine well enough. Its wont be a like a hot tanking but should be quite good.

Oil on your drain plug is probably the results of engine blowby from the filler cap area washing down the side of the block.

Is your rad an original honeycomb type, this needs to be cleaned up well, or replaced with a nice new aluminum rad as an option.

All these flush kits are meant for lightly crudded engines, not some 70 year old beast that had gallons of hard well water used at times and old antifreeze over the decades.

Stop looking for a quick fix, clean this out well, and your overheating troubles will be gone...........

[Mortimer452]

I've had much better luck with the Blue Devil stuff they sell at AutoZone.  I use two bottles and top off with water.

I'm also having overheating probs, I just keep using the Blue Devil stuff, drive for several days, then flush it out with one of those radiator flush kits that hooks up to a garden hose.  Every time I get a gallon or two of brown nasty water and my overheating issue gets a little better.  Obviously have some build-up in there but I'm too lazy to tear apart and clean with elbow grease.