813A1 radiator flush

[shootiniron]

813A1 radiator flush,please advise!

Decided to drain and flush the cooling system on the M813A1 w/ cummins.The initial flush was the expected brown wore out antifreeze.With the drain cock removed at the bottom of the rad. and the top rad. hose off I have been running water through it,then filling and running,then drain.Several times.I have then been just running water through the top rad. inlet and it runs clean out the bottom rad. cock till the last little bit then it turns brownish black.Put the water hose back in and fill watching the water run out the drain cock hole,same thing,will run clean then at the last it turns almost black.I've never had any engine temp issues or water in oil,as a matter of fact I just changed the oil and it was fine.
Is this just the sludge that builds up in the bottom of the rad.?Next weekend I'll get some rad. flush and run it through to see if it will clean up.

Any thoughts???

 

[cessnatwin]

they just get really really dirty! try putting some baking soda in it and running it, that will help neutralize any acids built up from worn out coolant, and wont hurt the engine, then flush it running you probably have a lot of crap and rust built up in the block. If you had oil in it the water would be all filmed up.

 

[Castle Bravo]

I recently ran my deuce for 2 hours with the hose in the top of the radiator and the draincock open. It went from almost solid black to just kinda dark during that time. Once I was satisfied, I closed it up and drove the quarter mile back to the driveway. I let it cool for a bit and when I drained that water, it was solid black again! I kinda gave up after that and just flushed it with distilled water a few times and added the coolant to the mix. I did put a coolant filter on as well and hopefully that will clean out some of the junk. Since I started messing with it, it has leaked a few times in a few different places. Apparently I fixed it until it broke.

 

[shootiniron]

I was kinda pleased that it was'nt as filthy as some I've read about here.When I get the time back I'll finish it up with a block heater and coolant filter addition,probably not for a couple weeks.To bad I cant get paid to work on my junk!