Coolant Flush Help

[aklead]

Hey, just picked up a 2003 919 and decided to do some minor preventative maintenance on it. I started with an oil change which was easy and straight forward and then decided to flush the coolant. I read on how to do it in the service manual and looked up a video on Youtube, ...seemed pretty easy. I moved the tank up, opened the coolant fill cap and the reservoir cap, pulled out the plug bolt and drained all of the coolant. Used a siphon to get the reservoir coolant out. Ran a garden hose through the system until I was getting clean water out the other end, then used about a gallon of distilled water to flush it through.

This is where I get a little confused from the guide I was following, they said pour coolant into the reservoir container, run the bike for 2-3 min then top off the container as it should have sucked the coolant to fill the system, then repeat this a few times. When I tried this, nothing! The container stayed right where I left it. I tried opening the cap under the fuel tank and then ran it for 2-3 more minutes and still nothing. ???

I then decided to fill the system through the cap that is under the fuel tank, got about 1.5 quarts in there, and 1 quart in the reservoir. The manual says 3.2... What am I doing wrong?!? Why isn't the reservoir being sucked dry to fill the rest of the system?

Any help would be awesome!!

[zaq123]

you should first put coolant in the radiator (cap under the tank), fill it.
Expansion reservoir doesn't take much of the coolant and it ultimately goes back into the radiator through a small hose connected just under the radiator cap.
Once your rad nice and full, start the bike and squeeze the hose to bleed some air, put cap back on. Run bike not 2-3 min but until it reaches normal operating temp so your thermostat is able to open. Wait until it cools, open the rad. cap and see if you can add some more coolant.

Did you remove thermostat when you flushed it? In any event, you will be able to put about 2 gal in it until it's full as your thermostat was closed and kept about 1 gal of coolant in the bike when you flashed it. You need to remove thermostat in order to flash the block well.

Don't worry about it. If your radiator is full, the cap and thermostat is good , you will be OK. Fill your exp. tank and ride you bike. Keep an eye on the exp. tank an fill it as needed.

Also check the hose from exp. tank to the cap and make sure it's not kinked

[firedave]

I just did this to my bike last week. The manual says to fill through the rad cap then fill the coolant reservoir to the max line. Then run the bike for a few minutes then rev the bike up 3-4 times to get any air out of the system. Top up, replace cap.

I do know that if you read the manual to quickly that it looks like it says to fill through the reservoir. Had to read it a couple times to understand it correctly.

"edit" Zaq beat me to it.

[rmb]

As per the manual, you have to fill the radiator and reservoir, start the engine, let run for 2-3 min., snap the throttle 3-4 times to bleed air from the system, stop the engine and top off the radiator and reservoir if necessary. Done.

Edit: Imagine that, in the time it took me to get my manual and type my response there were two more posts...

[zaq123]

I'm in the process of covering all of my cars and eventually bike to G12 (no silicates) coolant so I can keep just one type around. Key is to flush it very very well.
My VW is G12 (factory), I converted BMW to G12 last summer. Bikes are next.
I use Pentosin PENTOFROST SF. Excellent coolant and Napa has it available.
I've read too many articles which claim Honda water pump failures due to silicates. Call me crazy

[aklead]

Wow thanks for all of the responses! It is winter here so I can't ride for at least another couple months, but you think it is ok? Should I let it idle to full temp and see what happens to the levels?

Thanks again everyone!

[Mark919]

aklead,
Recommendations by zaq123 are totally on target.
My only concern is with the first post. I can't tell whether the engine and radiator had coolant during the first 2-3 minutes of idling when you first tried to fill it. I'd have to ask the more experienced mechanics how long an engine could run this way, if it had been drained...
After the initial fill and short idle period i found the radiator only needed a cup or so of additional fluid to top it off.
Mark