Coolant drain valve assembly

[1200fan]

Hi everyone,

As part of my never ending saga of trying to get my Vmax on the road, I'm now having problems getting the coolant sorted out.

I had to dump the coolant to replace the valve cover gaskets (good job I did as the coolant was black), but as part of this I tried to turn the drain valve bung and guess what, it sheared off.

I've found a 2nd hand assembly but guess what, the bolt holding the broken assembly to the thermostat is properly seized and after two days of penetrating oil, saws, impact drivers and swearing its not budging.

The next deadline for the bike to be on the road is in a few weeks...:bang head:

However looking at it I think I may not need to remove it? Looking at it the bottom hose of the Vmax radiator goes direct to the valve assembly.

It looks like the valve, when opened dumps the radiator coolant?

My bike doesn't have the standard radiator and as such there is no bottom hose linked to it.

Would this mean I could get away with flushing and putting new coolant in without having to go through changing the assembly?

Thanks again everyone :biglaugh:

 

[SpecOps13]

Got any Pictures?? I just can't visualize your set up...

 

[dannymax]

Maybe this will help. http://www.vmaxforum.net/showthread.php?t=7351&highlight=drain+cock+assembly

 

[1200fan]

Cheers, yeah I'll get pics up for you to show what's happened later on.

For the time being I've removed the pipe to the assembly coming from the bottom of the radiator filler neck to get the extra coolant out.

Cheers again! :biglaugh:

 

[[email protected]]

Can anyone confirm the actual function of the valve? My best guess is that its there to direct coolant from the rad straight to the pump, bypassing the thermostat, so the radiator can be drained. Woulda been nice of yamaha to build a rad with a drain valve on it.

I need to flush my coolant but I need to stay away from the valve. Mine suffered some heat damage. It could be repaired but that's a winter gig. I want to test ride this thing. My rad is already clean and empty. Seems like I could remove the hose from the rad to assembly to drain the rad.

 

[Rusty McNeil]

I'm not sure.

I left mine in the closed position and pulled the water pump drain plug and drained all I could get out of it.

Then opened that little valve and got maybe another cup or so if fluid.
For what that's worth.

Engine was cold at the time so t-stat should have been closed as well.

Also;
I ran mine several years in the "wrong" position.
Engine ran just as cool no matter what the position of the valve. I remember playing with it to see which way was right and never could tell a difference temperature wise.
The markings are a little vague to say the least.
It has markings on the valve but I never found any corresponding marks to line it up with.
Only after building the new engine, and in the process disassembling that valve, did I figure out when it's really open or closed by visual observation inside the valve.

If you need to know for sure whether its open or closed its easy enough to remove that small screw in the side and pull it out so you can look at it.
It's just an o-ring seal, if it ever leaks its pretty easy to fix by just taking it apart and greasing or replacing the o-ring.
Just don't lose the spring and ball bearing that serve as the detent cause it will go flying if you're not ready to capture it.

Or else I can go look and tell you for sure since mine is clearly marked now. My memory is shit and that's why I marked it.

If you just want to flush and don't mind the mess I'd just fire it up with the coolant cap off of it, insert water hose, and once its hot then pull the water pump plug and dump it while filling with water. You'll cycle the T-stat and have to be careful not to overheat by draining all the water out while t-stat is closed but I've never had any problems using this method.

 

[maleko89]

Correct, it drains radiator when performing a coolant change.

 

[[email protected]]

Thanks for the replies gentlemen.

 

[sdt354]

I try to move it at least once a season. The valve isn't well made, with the plastic hex that strips very easy. I should remove it and inspect the o-rings this winter.
Steve-o

 

[dannymax]

I try to move it at least once a season. The valve isn't well made, with the plastic hex that strips very easy. I should remove it and inspect the o-rings this winter.
Steve-o

Pretty sure the plastic bolt o-ring and the other end of the drain cock 90? o-ring are the same.....I have a very slow coolant leak in that area....99% sure it's the hose but how pissed would I be if I was wrong!!....so, the little o-rings, t'stat cover o-ring, hose and both clamps are being replaced....oh hell, might's well rebuild the H2O pump, long's the coolant is drained....and paint the plastic elbow too.

 

[dannymax]

And while we're on the subject.....why the hell did Yamaha orient that bolt to drain in a position that's about 18? off vertical?? :ummm:
Who on earth is ever going to look for a witness tick in THAT position? :confused2:

Stick the damn detent screw 18? off center and orient the friggin' drain bolt on a compass point....north, east, south or west!

I mean....east north east....WTF!! :bang head:

There, I've held that in far too long!! :rofl_200:

 

[PATMAX]

Dannymax said what I have been thinking since day one of dealing with this arrangement. I completely stripped and refinished this assembly and another one for my "Rattlecan Special".
I cleaned the spring and replaced the ball bearing and o-ring. I greased the entire pipe where the plastic draincock goes. While you have it out, trow it on the drill press and shoot a hole across the hex head so you can slip an appropriate sized allen wrench in the hole to open and close the drain valve or to pull it out to service the o-ring. Just be sure the hole is not too deep as to be buried by the tube it fits in.
I could never remember which direction is open or closed. If you can feel or see the ball bearing poking out the small round hole, you know you are lined up to drain. Can anyone read the raised lettering on that thing when it's on the bike?

When in doubt...Gas it !!!

 

[dannymax]

That's my problem too....take it all apart, clean & rebuild, study intensely to obtain a thorough and complete understanding of how it works......then totally forget it a month later! :bang head:

Just a hunch but I bet the guy who designed this is the same guy who labeled the reservoir switch! unk:

 

[1owner1985]

Where one of those ends of that assembly goes into the thermostat housing is there an O-Ring? I cant believe that will seal with just a bubble flare pushed into an aluminum housing. Nice pics btw.

 

[dannymax]

Where one of those ends of that assembly goes into the thermostat housing is there an O-Ring? I cant believe that will seal with just a bubble flare pushed into an aluminum housing. Nice pics btw.

There is an o-ring and it actually does seal (the allen bolted strap holds it tight)....just be sure your contact surfaces are nice & smooth & lubed.

 

[maleko89]

Sorry for lateness. Here's the drain valve o-ring part number.

93210-14579-00

 

[sdt354]

Sorry for lateness. Here's the drain valve o-ring part number.

93210-14579-00

Thanks Mark, the parts book doesn't show it. And the Stealer will tell you to buy the whole assembly when all you need is the o-ring. Same o-ring as the one on the tubing, that goes into the housing I believe. Inspect the tubing carefully when it's apart. If the outside is rusted, best to replace. It's thin. I try to keep paint on it.
Steve-o

 

[dannymax]

Thanks Mark, the parts book doesn't show it. And the Stealer will tell you to buy the whole assembly when all you need is the o-ring. Same o-ring as the one on the tubing, that goes into the housing I believe. Inspect the tubing carefully when it's apart. If the outside is rusted, best to replace. It's thin. I try to keep paint on it.
Steve-o

The o-ring on the valve is the orange type Steve-o, one on the metal tube is black (Viton or Buna N I believe) but I think I used the black one for the valve on Sallymax and it worked fine.

 

[sdt354]

The o-ring on the valve is the orange type Steve-o, one on the metal tube is black (Viton or Buna N I believe) but I think I used the black one for the valve on Sallymax and it worked fine.

That's true Dan-o. The one I took apart from an early motor was black, but the ones I ordered were orange.