Best way to flush the Coolant System?

[perrymedik]

I’m nearing the end of a long fix for my 49 P-18.  After I get the Fuel System Primed, and the Oil gunk cleaned out it will be time to reinstall the Radiator.  When I took it off it looked like heavy muddy water being poured out.  Makes me think I need to flush the cooling system before I fill it back up.

 

What is the best way to do this?

 

Also, any considerations on selecting a coolant to refill the system with?

Thanks!

 

Cory

[chopt50wgn]

Cory..............to do a good flush of the system, you should also drain the block. You want to look on either side of the motor. You should see a plug above where the oil pan bolts to the block. Get that plug out and flush all the old water/coolant.

  Once you get that done, there are back flushing kits out there. You can find them in any good parts place, NAPA, Advance auto etc. Then just follow the directions on how to hook it up. It's not rocket sceince and once you get that done , I would refill with any of the green/yellow antifreeze. I highly recommend staying away from any of the so called high mileage coolants like Dexcool, HOAT's etc.

  You also want to maybe use a good chemical flush when you back flush the system to help remove even more gunk and grime from the system. Prestone makes a good one which I have used in the past.

[_shel_ny]

I would pull all 5 welch plugs/freeze plugs/casting plugs/expansion plugs (Edit: add core plug as a name) from the driver's side of the engine. Lots of undesired stuff gets deposited there in the water jacket, and heavier deposits may not just flush.  New 1 5/8" plugs are readily available from auto parts stores. I found some poking around in parts drawers in the customer area at a NAPA. That was after I had already purchased a box of 12.

 

 

 

EDIT 2:  here is a thread with some suggestions. More can be found.

 

http://p15-d24.com/topic/20359-engine-block-flush/?hl=%2Bflushing+%2Bengine#entry195897

Edited November 2, 2014 by shel_ny

[perrymedik]

Chopt50wgn and Shel_ny:  Thank you for the recommendations!  I will hunt around for some plugs.  It is pretty chilly here and while I don't look forward to freezing my hands off getting those out I also don't want to risk having all of that gunk that has potentially settled in there circulating around and plug up everything else that I've worked on cleaning out making me clean it out all over again!

[_shel_ny]

There are some threads about removing the old plugs.

 

Sheet metal screw in the middle, ice pick, whatever. They will not be reused, so you can go ahead and abuse them getting them out. 

 

It isn't so much that that gunk and such will continually foul your coolant. It is more of  an issue of using the full volume/full cooling capacity of the water jacket. The space is there to have coolant, and any area loaded with gunk is not helping to keep the engine cool. 

 

You may find little. You may find a lot. You may find odd things.

 

Opening the drain on the side of the block may, or may not give you an indication of the gunk level.

 

The plugs you presently have could last a lifetime, or pop a pinhole from rusting from the inside at any time.

 

This is what I found in one engine. Made of metal.

[Don Coatney]

Removal as Shel mentioned.

 

 

Replacement plugs are available in brass as well as steel.

 

[perrymedik]

This post deleted because the user felt like an idiot 5 minutes later.

Edited November 9, 2014 by perrymedik

[_shel_ny]

This post deleted because the user felt like an idiot 5 minutes later.

Been there, done that, no shirt.

[perrymedik]

Would anyone like to hear a story?

 

Excellent!!

 

It’s a story of a young man who was trying take freeze plugs out for the very first time in his life on a very old, cantankerous, unfriendly flat six.

 

The young man just wanted the flat six to be cool.  Everyone wants to be cool right?  So starting with the top forward plug out comes the drill to make a hole, then in goes the steel punch  A few vigorous strikes with the mallet later the young man thinks that a little prying with the steel punch will pop that freeze plug right out!

 

Pressure applied . . . .

 

Pop!!!!!!

 

But not the freeze plug!  Oh no, that would be much too easy!  And if there is one thing this young man has learned is that nothing, NOTHING, is easy with this flat six.

 

Instead of the plug popping out, the tip of the punch snapped off and fell down into cooling chamber.  OF COURSE!!!!!!  I mean, why wouldn’t it?

 

Anyway, recomposed myself, and got the 5 plugs on the side out.  Grabbed my little flex claw and tried to fish it down to see if luck would be on my side and let me retrieve it.  Ummm, No.  Luck hates me! J  I was unable to get the claw down far enough.

 

This is what the rear bottom plug hole opening looked like.

 

 

So, thinking hard on what to do, I reached into the rear bottom hole and cleaned out as much as I could reach to the left towards where the tip of the punch was, then cut a side out of an old ATF bottle and fit it into the rear hole so that when I ran the hose in the top forward hole the water would flow down and the plastic piece would act as a diverter in hopes that it would catch the punch tip and I could retrieve it.  And you know what?  It worked!!!  Huzzah!  Luck mildly acknowledges me!!

 

After some flushing, and scraping in the chambers with a hanger I stuck my finger in the hole I had placed the diverted and could feel the punch tip!  Stuck my magnet rod in there and pulled it out!

 

 

Who knows what kind of damage that bad boy could have caused!

 

Any way after that I began flushing all the top holes with the hose and using the coat hanger to reach all corners of the cooling chambers by sending it down the Manifold Cover bolt holes and wiggling it around feeling out the sludge.  I would keep this up in an area until the water would run clear again and then move on to the next hole.  While am sure there is a little gunk hanging out somewhere, it is without question much better now then it was before.

 

Then I noticed that the towel I have covering the cylinders and valves was wet.  What is this?  Apparently I had bumped the hose and changed its angle upward and water was also flowing out the bolt holes and into the piston cylinders!!

Freak out #2!!

 

I shut off the water, soaked out all the water from the pistons, broke out the air hose and blew them out with a paper towel in front of the air to catch the water, then poured some Marvel Mystery Oil in the cylinders and liberally wiped down each cylinder in hopes that it will displace the water and prevent them from rusting.  Doh!!!!

 

Anyway, that wraps up the excitement for the night.

 

Now to find a place that sells the CORRECT Freeze plugs.  NAPA, love ya, but you ain’t the place!

 

More to follow in the chronicles, I’m sure of it!!

 

Cory

[_shel_ny]

But aren't you glad you popped those plugs out.

 

Plugs available many places.

 

NAPA can order the plugs if not in store.

 

The pic I posted was on the box I got through NAPA

 

You need the concave ones like Don's pic. 1 5/8" also come in a "cup"? shape. (like a lip all the way around.)  Not what you want, although I guess some have used them.

 

 

edit: napa # 3811014

Edited November 10, 2014 by shel_ny

[perrymedik]

Shel_ny:  YES!! Very glad I pulled them!!  I had picked up the the cup type from NAPA the other day and when I pulled these today I took them back and they didn't seem to have any in the system that matched.  I'll take your part number to them tomorrow and see what they can do for me.

Thanks!!

[_shel_ny]

Shel_ny:  YES!! Very glad I pulled them!!  I had picked up the the cup type from NAPA the other day and when I pulled these today I took them back and they didn't seem to have any in the system that matched.  I'll take your part number to them tomorrow and see what they can do for me.

Thanks!!

Thing with NAPA is, I had to buy a box of 12. Not that they cost that much, but 7 more than I needed.

 

Advance, 1 by 1, and in stock Edit: but seems that they are the cup style

Edited November 10, 2014 by shel_ny

[Dave72dt]

dorman # 550-023 (10), steel

 

              #560-023 ( 10) brass

 

1 5/8" concave expansion plug

[perrymedik]

Ordered new plugs!  They should be in tomorrow morning!  Thank you for the sizes and part numbers!

[Dave72dt]

Part numbers are assuming the 1 5/8" is the correct size for your app.

[Don Coatney]

Did I read somewhere (possibly on another forum) that the freeze plug in the head of your engine was leaking? Might have been someone else's engine I don't recall but the one in the head is a different size. 1 3/8"

 

Also when you replace the head use a thread sealant such as Teflon tape or another pipe dope as many of the head bolts penetrate the water jacket.

 

 

[perrymedik]

Don Coatney: Nope, not me.  I didn't have any leaks (amazing, right?).  I was pondering if I should put some type of sealant around the new plugs when I install them as a good measure.  I would hate to have taken out none leaking plugs and then the new ones leak!

 

I know I need to give the openings a good cleaning still.  Thinking of running some sand paper around them, or may a brass wire wheel on my Dremal tool.

 

Thoughts on that?

 

And now that you've pointed out that freeze plug, do you think I need to pull it, or since it is at the top like that are the chances for build up less likely?

 

Thank you!

Cory

[Dave72dt]

On plugs of that type, I like to use permatex # 2 sealant, then clean off the excess after the install.  My personal thoughts on silicone sealers is to stay away from them whenever possible.

[Plymouthy Adams]

I like Dave like the Permatex..was the way I was taught many moon ago when all waters still flowed north...

[Don Coatney]

I use this nasty stinkin stuff to help seal freeze plugs.

 

[perrymedik]

Permatex it is then!