Any recommendations for coolant system cleaners/flushes for aluminum components? It's time and instead of just flushing with water I thought to use some type of cleaner.

 

is the old Anti-freeze clear or nasty, if somewhat clear just flush with water !!!

 

Thanks for the reply. The coolant is clear, but old. I would typically just drain and refill with 50/50, just wondering about the age of the cooling system if a mild cleaner/flush wouldn't be a bad idea.

 

I've seen those cleaners open up pinhole leaks that probably would never have been a problem otherwise. Just flush it with water until it runs clear then refill.

 

Good advice above. I always drain and refill with some distilled water. Run that till fully warm and drain and refill again with distilled water. Do that till you have clean clear water on the dump. Then refill with straight DEXCOOL. That 50/50 CRAP is worthless unless you are just topping off.

Always use a hydrometer to check the coolant to water mix and adjust till its correct. If you use the 50/50 crap, I doubt that you will get the correct coolant to water mixture that you need for the system to perfor correctly.

Remember to BURP the cooling system at the steam cross over line fittings at the front/top of each head.

 

I was a water pump engineer for 6yrs.... just flush 3-4 times w/water.
TIP: If you can back flush *first* you might be able to blow debris out a bit more effectively. Especially on the heater core.

When I bring an old car home here is what I do
- Remove heater hoses at engine
- If heater circuit has a valve either hold it open or remove it
- Back flush the heater core with a strong spray from the hose. (not pressurized... just a strong spray)
- Flow water through in both directions until its clear.
- Remove T-Stat
- Remove bottom radiator hose
- Remove rad cap (or degas bottle cap)
- Spray water through block in both directions until water is clear.
- Spray strong water in bottom of rad but only for about 2 seconds. (this will break loose debris and it'll then flow out)
- Spray in rad top / degas until clear water flows.
- Re-assemble everything (new Stat if you want)
- Flill with water
- Burp system & drive 10+ miles
- Cool engine 4+hrs
- Drain all water and refill w/water. Burp and drive 10+ miles
- Cool and drain.
- Refill w/pure coolant. Burp & drive.
- Once cooled tweak water & coolant ratio to meet freeze spec.

 

I can tell you unless you have let the Dexcool get nasty, your internals are clean. I had mine apart and went through the block and radiator with a borescope, the internals looked new including the block around the cylinder walls. I wouldn't introduce any chemicals unless there is a specific reason, and even then I would be concerned.

 

That's how I like to do it as well. I find that just draining and refilling the radiator with pure dex (after flushing with pure water) puts the overall concentration right around 50% for most cars. Or at least it's close enough for Florida. If I lived in an area with hard freezes, I'd be a bit more **** retentive about checking the ratio.