Short Term Coolant Flush N Fill?

Title may a little misleading.

Last month my older son and I bought a 1996 Tacoma X-cab 4x4 with 3.4L and 5 spd. It only had 101K miles. I've been repairing minor things and changing fluids. Fortunately, a lot of service records came with the truck; TB was done around 60K miles.

Anyway, the current coolant in the radiator looks terrible. Since we will probably get another TB change around 120K miles by a Toyota shop, I was thinking of doing a flush-n-fill with universal coolant until then. I didn't really want to sink $$ in "expensive" Toyota-brand coolant that might only be in there for a year to year-and-a-half.

Thoughts on this? Universal coolant recommendations (Peak, Zerex, etc)? Thanks.

 

I've used the Zerex Asian Formula in my '03 Tacoma 3.4. I purchased from Napa.

Interesting article to read.........

 

that's what I used on my flush and fill. after 25k miles it still looks the same nice and pink. No issue whats so ever.

 

You don't need Toyota brand, just a good brand that says it's compatible. Ten years ago, coolants were only good for 2 year before the corrosion inhibitors were "used up". Now they claim to be good up to 5 years. And just because the coolant looks clean and cools the engine doesn't mean that the corrosion inhibitors are still working. If your cylinder head corrodes and you blow a head gasket, the cost of coolant will seem cheap. Also, you can drain and reuse the coolant if it's not old, so you won't have to waste all of it after a year.

 

Finally started the work today. With a cold radiator, I took off the radiator cap and found some dark brown thick sludge at the cap. Fluid appeared dark green - brown. First drain yielded about 7 quarts, and foamed up some while draining. Looks like either some standard green or gold universal may have been in it and possible reacted with another type - Dexcool maybe? Truck has been running fine with no overtemps at all, even on a 2 hour interstate trip. Put some TSP in the first distilled water refill and drove around with heater on. After cooling, second drain yielded 7 quarts again, and it looked like black coffee. Refilled with plain distilled water and drove around some more. Third drain still dark, but not as much as before. Refilled with plain distilled water and closed it up for the day. Will resume tomorrow and see how it progresses.

 

I need to do this! I've seen a few video's out there on YouTube. It's on the list!

 

I would reccomend doing another drain and then fill with water and 1 bottle of any brand of radiator flush. Then drive it like you're doing and drain again.

 

You are on the right track.

Was the water pump done with the last timing belt? Thinking not, as that would have required fresh fluid. If not, keep an eye on the weep hole, make sure your current work doesn't clean things up and create a leak. If it does, worst case is you do the whole service early.

When doing a full change for short term, you can use any anti freeze you wish. You only need enough to protect against the most severe cold you'll see. In Ala. I'd probably pick 0-10* as a 'just in case' number. The rest of the fill can be distilled water.

When you do the next full service, I'd do all new hoses, tstat, etc. leaving only the heater core and radiator itself as potential future issues.

 

For what it's worth, I'll never chemical flush again....your mileage may vary.

Keep flushing...lots of water.

 

Only got to do one drain and refill tonight. Drain is still brown in color (drain #4). Now I have no heat, so I wonder if HC is airlocked. Need to get more distilled water too. I may take off lower radiator hose to see if there's anything that won't pass through drain outlet.

**One more comment I forgot to mention when posting earlier. While I was checking the heater hoses to see if they were hot on either side of the water valve, I squeezed them. They felt kind of crunchy, like there is some build-up or something inside them. Now to take them off and inspect. Oh well.

 

Drained the radiator. Drain #5 still dirty. Added some more cleaner, refilled, and warmed up the truck to normal temperature. Still little to no heat. Let it cool down and drained the radiator. Drain #6 still dirty looking. Took off the heater hoses. They had small rust flakes and "mud" inside. Heater valve was okay; just cleaned the inside a little. Backflushed the heater core and got a fair amount of that same cruddy stuff out. Heater core is now flowing clearly. Took off the thermostat housing and it had some crud too, as did the thermostat. Flushed the radiator with the hoses off and got some more crud out. Spent all afternoon on this, and I think I am making good progress. I will replace all the heater hoses, radiator hoses, and thermostat, and refill it with distilled water a couple of more times to see where I am. Evidently, this is a combination of neglect and adding the wrong antifreeze. Just glad I caught it before a major catastrophe happened.

 

I had to flush multiple times after putting in a new cylinder head. The coolant was real bad from neglect and the leaking head gasket. I never got it completely clear, so at some point I just said F it and just filled with the proper coolant.

I don't know how committed you are, but there are some small coolant hoses going to the IAC and EGR valve that can get clogged too. That was on a 96 2RZ at least.

 

Took the radiator completely out and flushed it with the garden hose, through every opening. Got more crud out of it. Replaced all the heater hoses and upper and lower radiator hoses. Decided to re-use the existing thermostat (after cleaning it); used a new gasket and installed it jiggle valve down, after reading several posts about that. Refilled the system, warmed up the truck and checked for leaks - none found. Let it cool and drained. Drain was still dirty, but not as much as before. Going to check oil cooler lines tomorrow.

 

With that coolant sludge you had, and probably still have, you might want to try some type of acid or cleaner in the coolant. Vinegar works, it's acidic, but it's not a very strong acid. Might want to poke around on here:http://www.bobistheoilguy.com/forums/ubbthreads.php/forums/35/1/Cooling_System_Fluids_&amp
This forum is full of absolute fanatics and enthusiasts of oil and vehicle related fluids, like we are of Tacomas. I've learned and tried a few things from there.
One product the guys there like for radiator flushing is RM-25 or something like that. I've never tried it but I read about it after I used vinegar successfully in a coolant flush to rid the system of oil from a blown head gasket. I will try that stuff next time I have a condition that requires some type of flushing or cleaning of coolant system.

 

I disconnected the oil cooler lines at the oil cooler and got some more crud out. These lines are low in comparison to some others, so I guess they would collect any solid debris. I backflushed them as best I could with a hose and then reconnected them. Refilled the truck and drove around a little. Let it cool and drained it. The drainage still looked brown like tea, but had very little debris after I let it settle. I refilled it with distilled water only and drove it to work (15 miles) at highway speeds, opening and closing the heat valve to help purge air bubbles, etc. Temp gauge was fine, even in stop-and-go traffic. I'll drive it back home and drain after cooling down. I'm probably going to order some of that RMI-25 to help get any debris that may still be lurking.

 

Some of that "gunk" you're finding in the radiator may be radiator sealant "stop leak" put in by the PO to stop/hide minor leaks. Once you remove it (if that's possible)...watch for leaks.

 

Yeah, I've been watching real close and looking at debris, which appears to be rust specks / flakes. So far, no leaks (fingers crossed).

 

Ok, last night I was about to pull the trigger to get some RMI-25 off of Amazon, but when I read some of the customer reviews, one said (paraphrased) "make sure all the red coolant is flushed before using". WTH? Is this stuff a no-no for our coolant?

After driving to work and back (30 mile round trip) and letting the truck cool, I drained the system and it still looks like brown tea, but with only a little (less than a teaspoon) of very fine debris particles. I'm about to say the heck with it and go ahead and add the coolant. I've put at least 15 gallons of distilled water through it so far, not counting the regular tap (hose) water used to flush the radiator, heater core, and oil cooler lines while all were disconnected from the rest of the system.

 

If it's still brown, and you plan on keeping the truck, I'd keep flushing.