So a weeks ago i replaced my water pump and timing belt on my 90 4runner, 3vze. The coolant that came out of it was nice and clear. I put fresh green coolant (same as what has been in it since i got it 7 years ago) yesterday it started leaking again so i tore back into it. the coolant is rusty brown and the hoses have sludge in them. Where the water pump mounts to the block has a bit of surface rust on it now also. i was thinking about trying to track down some toyota red but the green that what was in there was fine. any one have any ideas how to stop the rust?

 

Coolant system flush, not just drain and fill. Toyota RED. Fixed.

:wabbit2:

 

I wonder if your not getting oil in there ??

 

Distilled water.

 

Killowatt
I am the technical manager at prestone coolants. Two reasons you get rusting and sludge. The rust comes from having air in the cooling system. Whenever you change coolant, you should really take the time to check and make sure it is completely full after the refill. That means checking it the next day after you have been driving it a bit and filling to the top of the filler neck.
The rust need air to form, no air in the system= no rust.
The sludge comes from having an excessive coolant concentration mix. Whenever the coolant concentration is too much, it will gel and form sludge.
What you need to do now-
Drain the cooling system and fill it with water and a quart of Prestone super flush. Run the car for at least and hour including driving it down the road. Drain the system, pull mthe bottom hose off to get as much out as possible. Fill with water again and run it for 15 minutes, drain again. Now fill it with a 50/50 mix of coolant and distilled or deionized water. Check it the next day to make sure it is completely full.
Now you done. Prestone extended life coolant is completely compatible with your Toyotas cooling system. In fact, Prestone is a coolant supplier to Toyota. Red? It is dye. Coolant color does not tell you what kind of coolant it is. All automakers like to dye theirs different colors to get you to buy from the dealer. That said, old "green" coolant is silicated coolant that really went out of style with automakers 15 yrs ago. HOAT or OAT coolants are what is used now. HOAT stand for Hybrid Oraganic Acid Technology. OAT is Organic Acid Technology.
Learn more at Prestone.com