I just changed out a cracked oil cooler and am trying to purge the system. I let the mud drain out for 3 days, and charged the system with air pressure about 10 times until mud finally did stop coming out of the block and radiator, though we all know there is a lot left in there.

I'm circulating a degreaser and water through the system right now, and had to slip some card board over the radiator to get it hot enough to open the t-stat. I will drain the radiator and block best I can, but what I would really like is to run water into the system and let it run out without it recirculating through again. I have 600' of garden hose that the sun heats up very nicely and would like to run this through and out.

Would I want to hook the hose to the supply hose at the bottom of the overflow tank, and if so where would I open the system and which side would I block off? OR . . . is this even possible with this system? I've read where there are parallel circuits in this cooling system. I know I need to have the radiator flushed and I am going to do so, but I wanted to flush the block also as best I can.

A cooling system flow chart would be nice, so a link to one if anyone knows of one, and any other sage wisdom one cares to offer will be much appreciated. Thank you. Kevin.

1999 F350 7.3 2WD Crew cab long bed. 330,000 miles oil cooler replacement most major repair ever done to her.

Edit: I had posted this earlier today in the wrong forum, and since then have made a lot of headway flushing the cooling system, but I would still like some input from someone more experienced than myself. Since I snapped the head of the bolt off, for the thermostat housing (the one in back! No way to get a drill bit on it for an easy out!!!!) I have lots of time to think about this. Looks like to me I'm going to have to pull the water pump to be able to drill the bolt to extract it. I was going to pull the radiator anyway so might as well replace the water pump too. It has 330,000 miles on it probably a good idea after all that sludge running thorugh it.

 

we use simple green at the shop to clean out the cooling system on the 6.0l when the oil cooler blows up and filled the coolant, we use 3 gallons of concentrate simple green, pore it all in and top off with water and then go and drive it hard and get it really hot, and then drain it and then put a quart of vc-9 in and top off with water and drive the same way and then fill and drain with straight water about 3 or 4 times till it comes out simi clear

 

Thanks - what is vc-9?

And do you leave the thermostat in while driving?

 

you can get the vc-9 from the dealer and it is a iron cleaner to remove any oil or stuff that is stuck to the block so it doesnt flake off down the road and plug something, yes leave the stat in other wise it wont get hot enough to thin out he oil to allow it to flow

 

I knew leaving the Tstat would not allow for high temps but while I flushed this afternoon I slipped cardboard if front of the rad so degreaser would run through system constantly at high temps - monitored gauge whole time and temps ran just a hair above normal so I thought it was more effective to clean walls of water passages.

I think I will continue to do the same but using the vc is another level of treatment I wold not have known about without your reply. Thank you dhb much appreciated great info.

 

Don't forget to pull the block coolant plugs for a complete block drain.





Sometimes no amount of flushing gets all the crud out of the lowest coolant passages.

 

I think a coolant filter may help clean up the leftovers.

 

you can back flush the radiator with a high volume high pressure hose. a fire hose that is fitted to most factorys on the big hose reels are perfect. the radiator acts as a big net most of the stuff that dislodges from your engine will get ccaught in the top tank. if you flush from the bottom out the top it will blast a lot out before it gets stuck in the tubes. my cooling system had stop leak tablets put in when it went in for a new steering pump(why i dont know) under warranty when it was only 14 months old. i only new they had done it when i looked at the workshop recipt when i picked it up. i should have flushed it out straight away but didnt. 6 months ago the temp gauge would start to climb when going up a hill towing my boat so i pulled the rad and removed the top tank, running water through it i had 13 tubes flowing in total the rest were cloged with that stop leak. i couldnt belive that it would only get hot when towing while that blocked.
so you could have lots of sludge in the top tank blocking tubes and contributing to the water discoleration a back flush will give it a big help. ultimatly all the cleaning could also make the radiator,heater,pipe work and welch plugs leak especially the rad and heater core cause are both made from aluminium and will most likely be in a bad state internally with corrosion from a unkept cooling system.
hopefully you caught it before it has corroded anything to badly causing the need to replace lots of stuff..