4th generation coolant drain and fill

[Carl_G]

I've searched the entire forum and can't seem to find a thread on how to do a simple drain and fill for the coolant. For our v6 and v8.

I don't need to drain the engine blocks. Is it as simple as draining whatever is in the radiator and then refilling the same amount into the radiator?




Thanks.

 

[DocMT]

I've searched the entire forum and can't seem to find a thread on how to do a simple drain and fill for the coolant. For our v6 and v8.

I don't need to drain the engine blocks. Is it as simple as draining whatever is in the radiator and then refilling the same amount into the radiator?




Thanks.

Depends if you want to just drain and refill or flush. If you decide to drain and refill, keep in mind that you're obviously only replacing the coolant that is in the radiator at the time and leaving the rest of the coolant in the block. That said, I'd probably flush it all out.

BTW, starting with the 2004 model year, 4Runners come with the pink long-life coolant that is good for 100,000 miles on the initial fill and then 50,000 mile intervals after that. The pic in your avatar tells me that you have an '03 model though...

 

[Carl_G]

I had it completely flushed last year and filled with LLC. So my plan -hopefully successful- is to drain and fill whatever is in the radiator with SLLC yearly. My theory is that this procedure will keep it fresh.

So just open the radiator cap and open up the radiator drain valve at the bottom?

 

[DocMT]

I had it completely flushed last year and filled with LLC. So my plan -hopefully successful- is to drain and fill whatever is in the radiator with SLLC yearly. My theory is that this procedure will keep it fresh.

So just open the radiator cap and open up the radiator drain valve at the bottom?

If you had it completely flushed and filled with the long-life coolant, then don't waste your time & money doing it every year. That's totally unnecessary. But if you insist on doing it anyway, then yeah, just open the cap and the drain valve at the bottom and let it drip right out.

 

[jeober]

If I recall the coolant capacity is about 2 gallons. Here's what I do on my V-6:

Warm up and then drain the radiator. You should get slightly under one gallon out - Do measure and confirm.

Replace this amount with water. Warm up and do this multiple times so that you finally have pretty much straight water in the system and therefore you have flushed the system.

Drain out the rad (needing about 1 gallon of water) one last time and replace with straight anti-freeze. This will get an apprx 50/50 mix into the system. Since I got somewhat less than 1 gallon out, I put the gallon remainder of straight mix into the overflow bottle so that it would eventually assimilate into the system,

There are side drains in the block (on the v-6) but this takes a lot of labor to access through the wheel wells. It's just not worth it.

 

[Carl_G]

Thanks very much, gentlemen.

 

[riverwolf]

If you check your manual, you'll see the system holds 13 quarts, which is a bit more than the 2 gallons mentioned. The radiator only contains about half of that, maybe even less. If you drain the block, rad, and overflow, you can get about 11 quarts out of the system.

Might as well drain it all and switch to SLLC as long as you're going to the trouble, IMO.

-Brent

 

[00328]

If you leave the radiator cap tight and open the pet cock on the bottom of the radiator the vacuum created will also drain the overflow bottle at the same time.
I have 60K on mine and just drained and refilled and will do it again in another month or so just to freshen up the coolant. I don't believe in leaving fluids in forever, trans, coolant, whatever, I don't care what the manufacturers want us to believe.
Preventative maintenance!
Just my opinion.

 

[jeober]

If you check your manual, you'll see the system holds 13 quarts, which is a bit more than the 2 gallons mentioned. The radiator only contains about half of that, maybe even less. If you drain the block, rad, and overflow, you can get about 11 quarts out of the system.

Might as well drain it all and switch to SLLC as long as you're going to the trouble, IMO.

-Brent

The v-6 holds 10.4 quarts and the v-8 is 13 quarts.

 

[KB084RUNNER]

I just do 2 drain fills every 100-110k with the premixed long life coolant. Never an issue with any vehicle yet. Then a drain fill every 50k after that.

I have been doing this for 30 years with every car, truck, boat I have owned. Never any issues. No water pump failures, hose failures, radiator failures, rusty coolant.

 

[Carl_G]

That's what I will do too. I don't like the thought of trying to drain the engine blocks. Thanks.

 

[DocMT]

I just do 2 drain fills every 100-110k with the premixed long life coolant. Never an issue with any vehicle yet. Then a drain fill every 50k after that.

I have been doing this for 30 years with every car, truck, boat I have owned. Never any issues. No water pump failures, hose failures, radiator failures, rusty coolant.

LLC hasn't been around for anywhere near 30 years. And SLLC hasn't been around even as long as LLC. Hell, even pre-mixed coolant is relatively new.

Methinks your drain & fill regime was using the old green coolant that you'd get in gallon jugs at the auto parts store.

 

[Carl_G]

LLC hasn't been around for anywhere near 30 years. And SLLC hasn't been around even as long as LLC. Hell, even pre-mixed coolant is relatively new.

Methinks your drain & fill regime was using the old green coolant that you'd get in gallon jugs at the auto parts store.

Sorry I meant ELLC. It needs to be mixed.

 

[00328]

Does it really matter if the coolant is orange or green or red or pink?
It's NEVER a bad idea to flush or drain and refill before some preset recommended time/mileage interval. If it's done properly only good can come from it.

 

[Carl_G]

It matters; especially when orange Dexcool was mixed with Toyota red coolant by mistake. I had to get it completely flushed because it started to turn into a brown sludge like liquid.

 

[00328]

Completely agree.
Key words here "done properly".

 

[ben550]

after draining and filling the radiator, how do you burp the system? Is it just by running the engine with the radiator cap open until the air bubbles pass? should i be parked on an incline, decline, or level?

Thanks.

 

[JB.]

after draining and filling the radiator, how do you burp the system? Is it just by running the engine with the radiator cap open until the air bubbles pass? should i be parked on an incline, decline, or level?

Thanks.

Probably don't need to do anything as the system is self-purging. If you'd like to do something, you can drive around with the heater on high for a little bit.

 

[ben550]

Ok, I read in other threads of people parking on inclines and squeezing the rubber tubing coming off the radiator to get the air out... just making sure it will work. I dont need air in the work messing with the temp on my way to work. I was going to drain and fill the radiator using zerex. Thanks.

 

[NuclearN8]

Ok, I read in other threads of people parking on inclines and squeezing the rubber tubing coming off the radiator to get the air out... just making sure it will work. I dont need air in the work messing with the temp on my way to work. I was going to drain and fill the radiator using zerex. Thanks.

When in doubt, follow the service manual...