I want to flush the remaining coolant from the block while I have the front end lifted. How tight should these plugs be when I put them back in and what sealant would you use, if any? I really don’t want them leaking since these plugs are normally inaccessible and lifting the front end at my place is complicated.

These are the plugs I’ve been shown to remove. I’ll dump in distilled water through the outlet port (removed the pipe) to flush it out - hope that’s a good plan. I want to use blue coolant instead of green. Later I’ll detach the heater core hoses and dump distilled water in each direction to flush it. I’d use the hose, but the water here has a high level of mineral content - well water system and the hose water wouldn’t be filtered at all.

Any input is welcome. Thank you

 

I would use the well water hose first if has a decent pressure to push with velocity and large flow any debris/rust/sediment particles in all available ports and directions. After flushed, then do whatever distilling you plan.

 

I’m told the plugs are tapered thread so I won’t use a torque spec or a thread sealant, just run them in until tight. Good idea to blast out the heavy crap with the hose although water pressure here isn’t great - 40 PSI max. Here I go.

 

Dude, you are waaaaay overthinking this.

Just push a garden hose into any available coolant port and let 'er go.

No need to invite another problem by messing with the block drains.

After the truck is back together and running you can flush to your heart's content with distilled water if you like, then drain and add a couple gallons of Prestone to get to a 50/50 coolant mix. This ain't the space shuttle.

 

Yeah I tried to get at those block drains and one was just unreachable because of the exhaust and blocking the wrench unless maybe you have a long extension and go in from the driver side tire. The other one was really stuck on there and I decided not to mess with it, so I’ll just flush using the other method.

 

Block drains are handy if the engine is in the vehicle and you absolutely need to get all the fluid out of the cooling system. Most people never touch them. The fact that your engine is on a stand makes taking out the block drains completely redundant. No point in fussing with them..

 

Thanks I think there’s still a good amount of crap in there even though I poured distilled water in, but I might use the hose later when it’s in the city (mountains have water that’s very high in mineral content and I’d worry about scale because I know what it leaves behind). Bugs me that I can’t really flush it completely, but those block drains are corroded and just looks like something I shouldn’t mess with.

 

I went through this myself and used the Prestone cooling system cleaner and flush kit; also used some extra clear hose/adapters to make it pretty simple to forward and back flush via the heater hoses. If your heater hoses have never been replaced you should probably order new ones since you will likely have to cut the old ones off!

 

Thanks man I’ve replaced most of the hoses - did that in about 2016 or so, but they’re still pliable. I can remember which I couldn’t get to, but it might even a power steering hose or something I can’t remember. Every rubber and rigid hose I’ve handled with this current project has still seemed to be in decent shape except I struggled with the lower radiator hose, so I damaged that and got another. I looked and the cooling system diagram and wondered how I’d get a good flush - so maybe I’ll try blasting from the heater core, figured I’d try going both directions like they say to do a reverse flush?

 

I found the back flush to be effective in pushing out the old sediment/junk and here is a helpful photo.