Draining the coolant system.

[PBJ]

My new to me 86 has been sitting for at least 4 years. The previous owner only put 400 miles on it last year. Before that the owner died and his wife kept it 3 years before selling it.

 

I don"t know when the last time the radiator has been flushed and the coolant changed so i want to do that before i get into the meat of the riding season. In my owners manual it shows two point to drain the system. a coolant drain cock coming down off the radiator and a drain plug under the water pump.

 

My question: Which of these two points do members use to drain their coolant? Is the drain cock plastic? will it break? or is the plug under the water pump easier to get to and open?

 

I'd love to know who has used either or both and could you only use one or the other? Thanks.

[SaltyDog]

The drain cock under the radiator is actually a valve that can be rotated to bypass the coolant flow around the thermostat. It is used when filling and draining the system to insure a complete drain or to get all the air out of a new refill of the coolant.

 

The drain plug under the waterpump housing is used to drain the engine block completely.

 

See this thread on the drain cock settings http://www.venturerider.org/forum/showthread.php?t=52580&highlight=coolant+drain+valve

[Snaggletooth]

"ON" at 2 o'clock for draining radiator.

 

"OFF" at 2 o'clock for normal running.

 

 

The water pump drain plug needs to be out for best drainage. The drain selector only rotates unless you remove the screw, spring and detent ball to replace o-ring.

 

When refilling the sytem leave the selector to "ON" and fill the radiator to the top. Start bike and allow fluid to circulate. (at idle) Once the fluid is staying up replace the cap and top off the over flow bottle. Set the selector to "OFF" and allow the bike to warm up and top off the overflow bottle again. Check as needed.

 

 

Mike

[dingy]

Mike,

 

I took the liberty off editing your post below, I may be incorrect in this, but it will be a 1st this evening.

 

Gary

"ON" at 2 o'clock for draining radiator.

 

"OFF" at 2 o'clock for normal running.

 

 

The water pump drain plug needs to be out for best drainage. The drain selector only Comes out when you remove the screw, spring and detent ball to replace o-ring. It will rotate without touching screw.

When refilling the sytem leave the selector to "ON" and fill the radiator to the top. Start bike and allow fluid to circulate. (at idle) Once the fluid is staying up replace the cap and top off the over flow bottle. Set the selector to "OFF" and allow the bike to warm up and top off the overflow bottle again. Check as needed.

 

 

Mike

[mkrieg]

Well thanks to the pics, I just realized that the drain valve on my 87 was set to the drain position for the past four years that I owned the bike. Of course when I changed it to where it was supposed to be, it start leaking out of the valve like crazy so I turned it back. I ordered a new o ring so hopefully that fixes that.

[Snaggletooth]

Mike,

 

I took the liberty off editing your post below, I may be incorrect in this, but it will be a 1st this evening.

 

Gary

 

Good point Gary. I know a few have removed the screw trying to change the setting with messy results.

[Snaggletooth]

Well thanks to the pics, I just realized that the drain valve on my 87 was set to the drain position for the past four years that I owned the bike. Of course when I changed it to where it was supposed to be, it start leaking out of the valve like crazy so I turned it back. I ordered a new o ring so hopefully that fixes that.

 

Those o-rings are a common cause of minor leaks during the colder months. A lot of guys have found puddles under the bike while stored for the winter and never have a drip in the warmer months.

 

But if they don't get moved once in a while they just are difficult to change position and start to leak. A good cleaning and a new o-ring should fix ya right up. The thread mentioned earlier here is good info on that.

 

Mike

[PBJ]

Mike thanks so much for getting back to me with all this good advice. One more reason why i absolutely LOVE This site. Thanks also to Salty Dog for posting the thread link i read through all that too.

 

My Honda Sabre has a radiator as well and its a simple procedure to drain because the coolant is routed through the frame But the over flow tank is under the right side panel Below the radiator level. Anyway Now I know where to go, what to look for and what might become a problem. Thanks again guys I really appreciate all the help!

 

Phil.

[PBJ]

Yesterday my son came over and we had our own little maintenance day. Changed oils and filters on my bike and his then i got to my radiator. First i remove the chin spoiler and discover the valve was still in the on position. So I loosen the retainer screw( harder than it sounds) and then checked the valve it moved with no problem .Next i opened the drain plug under the water pump to drain the coolant. What came out was very green indicating it had been added recently. What was disturbing was how much came out and that was maybe a little more than a pint! I know the engine and radiator combined had to hold more than that, but it also gave me an indication as to why the thermostat needle has been jumping up and down.

 

So after buttoning everything up i added coolant( with the valve open) let her run added more then shut the valve. Topped off the over flow bottle and was good to go. I took her out and the thermostat started to come up but only up off the needle to the "C". Even under some hard running. What I did forget to do was re-tighten the set screw to the valve. When I got home it was gone. Luckily I have the 85. I'll pull that one.

 

All in all i followed every ones instruction and feel confident "Black hawk" is ready for our ride to the mountains in a few weeks.Thanks again to every one for the good and thorough advice.