Cleaning coolant tank

[lragan]

When I drained the coolant today to put in fresh, clean looking liquid emerged from every orifice.  First time I have run an aluminum liquid cooled engine.  I like it.

The common service manual calls for removal of the reserve tank, rinse, and replace.  Getting it out was a bit of a trick, and rinsing it did nothing at all.  There was a coating of green-black substance on the inside of the tank, right to the "max fill" line.  This is particularly annoying, in that it is impossible to see the liquid level from the outside of the tank, as was intended.

I tried removing it with detergent and with bleach, to no avail.  So I called my son the chemist, told him the tank is made of high density polyethylene, and asked if pool acid ("Muriatic" acid, really HCL) would damage the tank.  Assured that it would not, I used a little to clean the tank.  That works quite well.  The deposits dissolved as the acid was poured into the tank.  I swooshed it around a bit then poured it into an old, empty acid bottle.  A few rinses, and the tank was ready to be reinstalled. 

Removing and replacing requires to hold your mouth just so, and it is helpful if you have a strong hemostat clamp to compress the wire springs which secure the tubes to the tank bibs. 

The residue had a dark green color.  The ethylene glycol I use is green in color, and that could be part of it.  Without analyzing what it was, I can only speculate.  I note that Aluminum oxide is black in color, and Copper oxide is green, so perhaps it consists mainly of these two components.  Whatever it is, pool acid will clean it right out.

Caution is advised.  Pool acid will eat your skin and your clothes, so you need to be careful handling the stuff.

[hootmon]

good tip..
THanx

[L J VFR]

This is particularly annoying, in that it is impossible to see the liquid level from the outside of the tank, as was intended

Lawrence, I have found one and only one place to see the coolant level in the reserve tank.  With the bike on its side stand go to the right side of the bike. (The side that the brake stay rod is on) and  bend down and get eye level with the gas tank.  Now look in front of the side cover and there is a gap in which you can see the coolant reservoir and the coolant level.   Took a while for me to find it, but I can find it in a flash now.  Oh and don't forget to hold your mouth right....

[lragan]

Good tip, Lance.  I have been removing the side cover to check the coolant level.

Now that the tank is clean so I can actually see the coolant, and with your hint, I will check it more often.