Water Pump Change (Part 3/3)
Page 1, 2,
Flushing the coolant system
Here's what I found to be the simplest for me. There are a few
other ways to do this, e.g. using the radiator drain cock. But the drain cock
on mine is plugged, so that didn't work.
1) Remove the drain bolt on the coolant pipe going from the radiator
cap to the radiator, the red circled one below (leave the other bolt on, unlike
the below pic). Then without the car running, the rear of the car higher
than the front, place a garden hose at the radiator cap, and begin running water
through. Run the water through, until it becomes clear. Of course this may take
a few pan-fulls. So watch the level of the pan closely. A second person to run
the hose while you monitor the pan during this entire process helps tremendously.
Be prepared to get your hands dirty when placing the bolt back on as it is still
draining out and your pan is full. Replace the bolt when done.
2) Next up is flushing out the radiator. (This can get messy,
and it is possible to skip this step if you don't want to clean up after yourself)
Remove both upper and lower hoses on the radiator, by moving the spring clips.
Then place the garden hose into the upper hole in the radiator, draining the
water out of the lower one. Flush it until clear water comes through, and then
replace the hoses.
3) Now, use the drain bolt on the coolant pipe, that leads to
the thermostat (red circle, leave the other bolt on, unlike shown in the below
pic). Run the garden hose from the radiator cap flushing out the system from
the radiator cap, up through the radiator and back halfway under the car. Again,
once it turns clear you're done with this step. Replace bolt.
4) Now for the engine block and the rest of the way up this pipe.
Make sure all coolant bolts and hoses you removed before are securely fastened.
Fill up the system with water from the garden hose, until it's full in the radiator
cap. Start up the car, with the heater control set to hot (no need to turn the
fan on). Monitor the level in the radiator cap to keep it topped off. Once you
see the water start to bubble over, place the radiator cap on halfway (to the
first click). When the car approaches normal operating temperature, it is time
to remove one of the coolant pipe drain bolts. (mine was about 2/3 the way up
to normal operating temp when I undid the bolt) Have the person that is running
the hose, be ready for when you remove the bolt, you would like to keep the
coolant level topped off. Be very, very careful when undoing the bolt.
The coolant will be hot and it will come out of the hole fairly quickly.
I'd suggest wearing a good set of gloves when doing this. Just make sure not
to drop the bolt in the pan. When the pan is almost full, replace the bolt.
Again this will be messy, and the coolant coming out of the hole will be hot.
Empty the pan and keep the garden hose running to top off the level. Once the
pan is empty, position it again and undo the bolt, repeating this entire process
till the water is clear. After a few times, the coolant cools down from the
constant running of the garden hose water running through. So it becomes less
Now repeat this process again, but with the other bolt on the
coolant pipe. It won't take near as long doing this one. Keep the car running
during this entire process, making sure to keep the coolant level topped off.
Here's a pic of the first night of flushing the system, over 8.5
gallons. About 2.5gallons came from draining the car initially (I ran out of
containers). This was the morning after, before taking the containers to empty
at the local recycling center. Once you notice that the coolant is starting
to thin out it is probably safe to dump in your yard. Don't quote me on that,
save the environment...
5) When you are satisfied with the color of the water coming out
of the coolant pipe, turn the car & garden hose off, and drain as much of
the water out as you can. Then start filling the system with the Toyota coolant.
Follow the repair manual for the filling procedure. Below is just a pic of the
Toyota coolant mixed with water, 50/50.
Overall, this wasn't too terribly bad a project. It was my first
'big' repair on my '2. I worked on it for 3 nights after work. I screwed up
the first night, installing the pump and had major leakage when I went to fill
it up with water. The second night tearing everything apart and putting it back
together again was really easy as I knew what all had to come out and how to
get to everything. I also started the coolant flush the second night, filled
the system with the Prestone Coolant Flush, and drove to work the next day.
The third night was spent flushing the coolant system completely and thoroughly.
This time I had a friend help me which sped up the process alot. I would figure
a good long weekend day to do this, especially if you are going to flush the
system out well and if you haven't done the water pump or timing belt before.
But if I had to do it again, it would probably only take a few hours. Just be
prepared to move from working under the car to working over the car to working
under the car to ....
Hopefully, these instructions will help in giving an idea of what
all needs to come out. That seems to be the biggest problem with the BGB. Good