Hey guys, since rebuilding my engine, I have been running 100% water as coolant, with a bit of 50/50 mix because it was getting a bit hot over the summer. It's now nearing freezing at night and I need to put antifreeze back in, my question is what would be the easiest way to get a perfect 50/50 mix again? I'm thinking I will drain the rad, reservoir, then fill the rad back up with water and run the engine up to operating temp then drain the rad again, finally, I'll run the engine with the lower rad hose disconnected to get all the water out of the engine that I can. Then I will add 50% of the coolant capacity straight concentrate and fill the remaining up with water to get hopefully close to a 50/50 mix. I found on another thread the capacity fully dry is 12.1 quarts, let me know what you guys think here!

Thanks in advance,
Zach

 

I do basically this. Fill with distilled water, drain the proper amount to then fill with concentrate and get to the target mix %.

George

 

Yep, drain and put in 6.0 quarts of concentrate. If it all won't fit in the radiator, drain the coolant reservoir and put it there. It will mix in, gradually. First I would verify the 12.1 capacity with a factory manual!

 

My process is to pour 1/2 gal of concentrate into the rad, top the 1/2 filled jug off with distilled water and pour the remaining half of the water into the radiator. Shake the gallon of mix and add it to the radiator. Then I pour 1/2 gal of concentrate into the empty container and top both of those containers off with distilled water. At that point, I have two gallons of 50/50 mix. I top the rad and the overflow reservoir off and mark the container of the remaining mix with a marker so I can remember what it is when I need it later.

 

When I dropped the lower rad hose only 4 or 5 litres came out. It didn't occur to me to run the engine to drain the full 11 or 12 litres.

If you only remove 6 litres for example, the remaining 6 litres will be the strength of the old coolant, and it will dilute the new coolant. So maybe try to measure the amount of coolant that you drain.

After draining the rad, I mixed 50/50 in the jug and then topped off the rad. Then I ran the vehicle for 15 mins or so to mix the old coolant with the new, and then repeated the process several times. This is to fully flush the old dirty fluid.

If the concern is strength only, use a coolant tester to measure the strength.

 

I disconnected the heater core and ran water through it backwards of the normal flow. It heats a lot better now too. Low pressure though, don't apply high pressure to it.

 

Thanks guys, I put some concentrate in yesterday and it seemed to be doing fine. SEEMED, I thought I smelled sweet coolant all day and sure enough, when I was driving home I noticed a puddle of coolant where I park under my truck, then I looked at the front of my truck and it was dripping coolant like mad from the driver's side. I took a look at it for a bit and it seems to be coming from around the engine, not the rad. However, it was dark so I decided I will wait until tomorrow and take the skid plates off to see where it's leaking from. This is a very strange coincidence I must say, when I saw the coolant leaking the first place I looked was the lower rad hose that I had off yesterday, but all dry.

 

I've had more than one leak after a coolant flush. It's as if there was a leak that was sealed with debris that got knocked loose during the flush. My personal solution is to add some stop leak to cure the problem and it usually works. That's my solution but it might not be anyone else's.

 

Thanks Walleye, I'm not a big fan of using that stop leak myself I'd rather just do the job the first time and get it fixed. That being said I believe I have found the leak, it's the coolant drain plug to the right of the plug-in heater. I had my eye on this before as I saw a bit of what looked like water around there while I had the driver's fender off and now it seems the antifreeze made it leak a lot worse. I should have just fixed it then! When I put this drain plug in I used the thread sealant specified in the factory manual, I have a picture below. Les, I seem to remember you saying to use pipe sealant or something like that? If anyone has any suggestions to get a good seal here please chime in, I will probably drain the rad soon and pull that drain plug out, hopefully after awhile it will stop completely out of the drain plug and I can try to seal it again.

 

Zack, are you sure it isn't the freeze plug heater that is leaking where it fits in the block? It has an o-ring that could be leaking and it looks like it may be.

As for the drain plug, just tighten it a bit more if you see it actually leaking and it will be fine. What you used as sealant when you had it out was exactly what I meant - no need to remove the drain plug again.