I currently have prestone green coolant (good or bad?) and I'm going to do a flush and fill soon.

Is it okay to just drain and flush radiator a few times and add Toyota Red coolant in the end so that it mixes with the old prestone?

 

I did this with my 2002. You're going to have to do more than flush a few times. I had to flush about 20 times.

1)Empty radiator.
2)Fill with distilled water.
3)Run car to operating temp.
4)Rev engine to 2500 rpm 3 - 4 times.
5)Let cool
6)Repeat

Do this until the water comes out clear. Then fill the radiator with 100% Toyota Red (the rest of your car will have distilled water). This will give a near 50/50 mixture.

 

distilled water... that would be water from tap or the gallon jugs in the supermarket?

20 times? jeez...

i read the DIY guide on motorvate, but didn't answer the above question. how will filling with 100% give near 50/50 mixture? the engine holds 50% of the water?

 

First off, you really want to use a silicate free coolant. Typically, unless its marked on the bottle SPECIFICALLY that its silicate free, it isnt. Prestone green is, as far as I know NOT silicate free.

I did this around Febuary, and it took about 11 or 12 gallons of distilled water to flush it clean. I then drained the radiator and filled with Toyota REd and tested. It came out very close to 50/50.

As for draining the water in the radiator and filling only with coolant, yes I believe that the radiator hold 48-49% of the cooling system.

DONT use tap water, as it contains minerals that will build up and could cause clogging in your cooling system. Only use distilled water for flushing and filling of your radiator.

 

Yes. Once the water comes out of the radiator clean that means the engine is filled with clean water. The engine holds half the capacity, the other half comes from the radiator.

Listen to Colonel...don't know where I pulled 20 from. It was around 10 to 11 gallon jugs of distilled from the super market.

 

thanks for the help guys... much appreciated.

for those that wonder (just like i was) why use silicate free... read the link below under considerations...

http://pages.infinit.net/mcrides/eng...ne_coolant.htm

coincidentily... this also answers the question that the initial poster asked. don't mix silicate and silicate-free together.

those guys at strauss auto are gonna hate me... i keep buying stuff, and then going back to exchange it for something else because of something i read on the forums.