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RADIATOR FLUSH ADVICE

B

bugout

NAXJA Forum User
Location
Florida EVERYDAYS forcast: Hot and humid with a 50
I read all the treads but now I'm looking for the most up to date information.

WHAT IS THE MOST EFFECTIVE WAY TO FLUSH YOUR RADIATOR AND HEATER CORE AND WITH WHAT CHEMICLES?

Is it the old fashioned powdered dishing detergent method? The control CLP method? The old Prestone standby? NAPA ZEREX? Take it to the carwash and power flush it with the hot soapy water out of the high pressure gun? I don't want rumors or what your grandpa told you! I want REAL WORLD results, something that we might even be able to turn into a sticky!

Thanks in advance,
Chris
 
dishwashing detergent is only good for a cooling system that's been contaminated by oil.

The backflush with a hose method is fine for getting sediment and crap out of the system.

The chemical ones are good for removing corrosion, usually left behind because someone filled it with water and not coolant. They're also bang up at creating leaks.

If your system was in good shape and not full of rust, don't use the chemical flush, just run it with the garden hose until it comes out clean, drain and fill with the proper coolant. It is not rocket science to flush a cooling system.
 
The prestone chemical flush treated me pretty well. I used it 2 or 3 times in my jeep because the PO had been putting straight water in. The coolant was black.

Each time I left it in there about a week since its not my daily driver. Each time I would flush with the flush kit using a tee on heater hose line. Eventually, the coolant started looking clean and staying clean for now. I have a coolant filter but haven't found time to put it in. If you follow the directions on the chemical and flush kit you probably can't go wrong.

Like 87manche said though, you may not need what I needed. Just after flushing use pure coolant (not 50/50) put in 6 quarts then fill with distilled water.
 
Get the Prestone flush and cleaner, not the 10 minute super flush. I would first use a garden house to flush out the system the best you can. Add the flush and cleaner and drive for 200-300 miles.

Flush till it runs clean, fill with distilled water and conventional green antifreeze.

My 87 is all original cooling system, and I had no leaks with the less harsh Prestone. There was still some rust type particles that showed up in the coolant filter after 1200 miles. But not too bad, so the stuff works.
 
My strategy also depends on the condition of the cooling system.

For mild, I just flush with water.

For moderate, I use a citrus based cooling system cleaner/additive available at any parts store

For severe, I sometimes use multiple citrus based additives, or if really bad, I get the heavy duty cooling system cleaner.
 
birchlakeXJ said:
My strategy also depends on the condition of the cooling system.

For mild, I just flush with water.

For moderate, I use a citrus based cooling system cleaner/additive available at any parts store

For severe, I sometimes use multiple citrus based additives, or if really bad, I get the heavy duty cooling system cleaner.
Click to expand...

What do you call heavy duty cleaner? My heater has never really got hot and my overflow bottle is a little brown. BUT I'm not overheating nor do I have any leaks.
 
Citrus cleaner is supposed to be one of the best, but sometimes its easier to change the radiator if its loaded up with gunk. I'd look real good at your coolant hoses, if they are many years old they could be falling apart. They often deteriorate from the inside out.
 
md21722 said:
Citrus cleaner is supposed to be one of the best, but sometimes its easier to change the radiator if its loaded up with gunk. I'd look real good at your coolant hoses, if they are many years old they could be falling apart. They often deteriorate from the inside out.
Click to expand...

Very good advice here.....
 
bugout said:
What do you call heavy duty cleaner? My heater has never really got hot and my overflow bottle is a little brown. BUT I'm not overheating nor do I have any leaks.
Click to expand...

You're over thinking this. Use the Prestone, or go to NAPA and ask for some citric flush. Experiment. This hobby is about having fun and learning something:yap:
 
Well...

The Old School version of a radiator flush involves using White Vinegar as the acidic component of the flush. Over time, scale deposits form as the minerals precipitate out of solution. It is for this very reason that I only use Steam Distilled water in my cooling systems.

To use the vinegar, drain the coolant, cold engine. You want as much out as possible and I will disconnect the lower hose to drop as much as possible. Now, this is going to sound odd but... Put the back axle up on jack stands as high as you can. Or, if your driveway is slanted, park the Jeep so that it points down hill. All this is to get the old coolant out.

Once it is out, put in the Vinegar, full strength. A couple of gallons will do nicely. If you do have to top up the radiator, use the distilled water. Start the engine and allow it to come up to operating temperature. Shut down and allow to cool. Drop the mixture out of the system and repeat until what comes out looks like what went in.

As an example, the '98 I am now running needed a flush in about the worst way. The first pass at the flush, what came out was black and rather chunky...

Three flushes later, it looked good enough to run the Prestone product. One thing though, between every chemical flush, you really need to give it a thorough water flush. For that, a garden hose and back flush fittings work well.

IMO, the trick is to get as much of the tap water out as possible prior to installing the coolant. Consider using Distilled water so that this never has to be done again. For the final system fill, I put the front end on jack stands to promote getting the air out quicker.

Also, if the thermostat gets replaced in all of this, be sure to drill an air bleed hole in it and install the T-Stat with the hole at the top.
 
O-Gauge Steamer said:
Now, this is going to sound odd but... Put the back axle up on jack stands as high as you can. Or, if your driveway is slanted, park the Jeep so that it points down hill. All this is to get the old coolant out.
.
Click to expand...

it's way easier to just pull the block drain plug.

rad3.jpg
 
O-Gauge Steamer said:
Well...

The Old School version of a radiator flush involves using White Vinegar as the acidic component of the flush. Over time, scale deposits form as the minerals precipitate out of solution. It is for this very reason that I only use Steam Distilled water in my cooling systems.

To use the vinegar, drain the coolant, cold engine. You want as much out as possible and I will disconnect the lower hose to drop as much as possible. Now, this is going to sound odd but... Put the back axle up on jack stands as high as you can. Or, if your driveway is slanted, park the Jeep so that it points down hill. All this is to get the
the old coolant out.

Once it is out, put in the Vinegar, full strength. A couple of gallons will do nicely. If you do have to top up the radiator, use the distilled water. Start the engine and allow it to come up to operating temperature.

Shut down and allow to cool. Drop the mixture out of the system and then repeat until what comes out looks like what went in.



Now that should be a sticky! Thank you o-gauge steamer!

As an example, the '98 I am now running needed a flush in about the worst way. The first pass at the flush, what came out was black and rather chunky...

Three flushes later, it looked good enough to run the Prestone product. One thing though, between every chemical flush, you really need to give it a thorough water flush. For that, a garden hose and back flush fittings work well.

IMO, the trick is to get as much of the tap water out as possible prior to installing the coolant. Consider using Distilled water so that this never has to be done again. For the final system fill, I put the front end on jack stands to promote getting the air out quicker.

Also, if the thermostat gets replaced in all of this, be sure to drill an air bleed hole in it and install the T-Stat with the hole at the top.
Click to expand...
 
The thing is... Vinegar is sort of a "wonder" cleaner. Good for all sorts of stuff actually.

For me, I replace my coolant every 5 years as it does, IMO, "wear out"

Up here where I live, losing coolant from the over flow tank is just a normal thing. The altitude at my place is way better than 6,000'. Couple the low ambient air pressure plus the 210(F) operating temperature and you have coolant that is transferring back and forth that is hot enough to lose the water content. Boiling point of water here is real close to 200(F). This is because the average ambient air pressure is 12.5 PSIa as opposed tp the 14.7 PSIa you folk at sea level get to enjoy...

I just went through this with my Wife the other day. We recently scored a '98 ZJ with the 5.2 Litre and, as a matter of course, we topped up the over flow to the full mark as part of our normal "new to us" maintenance regimen. Two days later, the level had noticeably dropped. A normal thing up here.

Still, it does tend to surprise.

At the end of the day though, I strongly suggest that using distilled water is the best possible solution. Again, if there are zero minerals in the working fluid, then zero percent of the fluid can precipitate out of solution gumming up the works.

More expensive? Depends on how you define expensive. For me, I am willing to pay out a little more now to avoid large payouts later.

I know.... I am always on about spending large on quality. I realize that this puts me at odds with those whose primary interest is in spending the least. But, at this point in time, I am on a fixed income (forced into retirement 2008 due to health "concerns") and I still refuse to go cheap as it is less expensive in the long run to go with quality.
 
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