Cool/Heat: simple radiator flush

[mch]

Members, can you walk me through the process of a radiator flush? After opening up the valve on the bottom of the radiator and draining, what do I do next to flush out the radiator, engine and heater core?
Thanks in advance, please keep it simple
Mark

[studegary]

Members, can you walk me through the process of a radiator flush? After opening up the valve on the bottom of the radiator and draining, what do I do next to flush out the radiator, engine and heater core?
Thanks in advance, please keep it simple
Mark

It sounds like you want a cooling system flush, not a "simple radiator flush".

[mch]

probably yes

[tsenecal]

For flushing the radiator, it would be best to pull the bottom hose. You will get full flow, and larger particles will have an opening large enough to wash out. To flush the entire cooling system, the best way is to pull the soft plugs on the side of the block, and dig out what debris you can, with flushes in between. Next best, would be the pipe plugs at the lower rear corners of the block, but they will not allow much flow, or larger particles to escape. To flush the block, you would also need to pull the thermostat housing, for a place to flush from. Good Luck with it.

[TWChamp]

To flush the cooling system in my Model A, I ran vinegar for 30 days, then back flushed by connecting a sump pump to the block. I also removed the radiator, turned it upside down and used the sump pump to back flush it. I didn't know about Rust911 at the time, but I'd use that the next time to dissolve the rust particles. The vinegar made a mess, but it got the job done. You need lots of flow with some pressure to dislodge the junk usually packed in around the rear of the block, and the sump pump did a great job. Luckily Studebaker engines have core plugs, which my Model A doesn't have, which can be removed to help clean out the blocks.

[Greenstude]

When my '47 Champion was running far too hot, the radiator was the cause that was least suspected. Externally it looked perfect. When flushed with a garden hose at full city water pressure, the water ran through it without a problem and came out perfectly clean. As a last resort it was taken to a competent radiator shop. They cleaned it with acid, then pressure tested it. It sprayed like a lawn sprinkler. The corrosion and crud were the main components of the rad. Since it was recored there has been no heating problem. It was expensive, but definitely worth the trouble and cost.

[Blue 15G]

I have a female garden hose coupling soldered to a short piece of copper pipe, maybe 1/2 in. diameter or so. Something I found in grandpa's old collection of stuff years ago. You can cobble up something similar. Or I think you can get a plastic fitting kit at an auto parts store. First drain whatever coolant will come out of the radiator and close the petcock. Remove the heater hose coming off of the water pump, and plug the pump fitting off. Clamp the coupling into the heater hose. Attach a garden hose to the fitting on the heater hose. Remove the top radiator hose at the thermostat, loosen the clamp on the radiator side of that hose and reposition the hose so it can drain away from the car, or use a different piece of old rad hose that works better. Keep everything away from the fan of course!
Open your heater valve, turn on the garden hose full blast, and soon you will get a tremendous amount of rusty water out through the top rad hose. This is a reverse flush, essentially. You can run the engine during this process if you want to, it won't overheat, but it's not really necessary. After the water comes out as clean as it will get, remove the side block drain plugs (or one drain, on a 6 cyl), and again run more water through these until the water is pretty much clear out of the block drains. After this, it's a good time to replace any rad hoses or heater hoses that have been on the car for a long time.
I've flushed out cooling systems for years using this procedure and have never had to go through the aggravation of replacing freeze plugs. This method will remove a ton of rust and crud, and your heater will work great afterwards also.

[Blue 15G]

I also want to add that, yes, the more drastic method of removing freeze plugs and digging around inside the block may definitely be needed in some cases, but the method I described often cleans out the cooling system very well, and it never hurts to try the simpler methods first.

[mch]

Wow, a great amount of information. Thanks again to the knowledgeable members who teach those who want to learn.
thanks again.
BTW, my 64 Super Hawk will be ready for paint probably in a few weeks. A complete body disassembly and removal of all S.S. and chrome. A concourse paint will follow.
thanks again,
Mark

[altair]

I don't think any amount of simple flushing would remove this.

[TWChamp]

That looks like a job for RUST911 after you scrape out all you can and install new core plugs.
Maybe you could even install "Red Cap Plugs" to cap the holes while Rust911 does it's job, then remove them and give it a good second flushing.

[mch]

Ill do the full engine and radiator flush soon, Ill keep you all posted. thank you again for all the suggestions. I really appreciate the forum
Mark

[Hawklover]

Just curious, while you are in the midst of changing the coolant will you be enjoying your private stock of Cohiba Talismans???? I have been told they keep the stress level way down when working on old automobiles.

Ill do the full engine and radiator flush soon, Ill keep you all posted. thank you again for all the suggestions. I really appreciate the forum
Mark

[Hawklover]

You should have your mechanic remove the rear block drain plugs. In their place put in two drain cocks, like the radiator has. Then in the future you can fully drain the block and radiator. You will need two reducers for the drain cocks.

Members, can you walk me through the process of a radiator flush? After opening up the valve on the bottom of the radiator and draining, what do I do next to flush out the radiator, engine and heater core?
Thanks in advance, please keep it simple
Mark