Mysterious water leaked finally solved

[Chrisj CMA]

Ok, so a friend of mine who I frequently help with maintenance discovers that he has an antifreeze leak somewhere on top of the block on his Valkyrie.  It did not seem to be the usual thermostat housing top hose, so we thought and figured it had to be the little funky weird shaped O-rings on the water pipes as the thermostat housing was wet but below the hose, even below the seam between the two halves of the housing.

So we attempt to replace the O-rings from behind the radiator by pulling the thermostat housing and then removing the water pipes.  So far so good, the bike is a "97 with over 200,000 miles so the O-rings looked like they needed replaced, we felt we were on the problem.

Well let me tell you re-installing them pipes and the thermostat housing blind (from the front) is no easy task.......Didnt work the first time....big leak.

Now, we remove the airbox and carbs so we can work on the water system directly from on top.  That goes much better and now all the pipes and housing fittings are dry.  Bolt it all back together carbs and airbox...WHEW!!!  fire her up amd all looks good.  Wait a second.......CRAP! as soon as pressure buids there is that same leak just like at the beginning seems to come from one of the three bolts that holds the upper half of the thermostat housing.  How can that be? 

After much thought we thought, the only part that has the ability to just fail on its own would be that plastic upper half of the thermostat housing, so he ordered one of them.

BINGO, that fixed it, and most likely the O-rings were never leaking, but they were old.

So you can have spontaneous failure of the upper half of the thermostat housing.........it cracked right on the mold seam, this is a fine crack that doesnt even leak until the system builds up pressure

Who knew?






 

[HayHauler]

WOW!  and DAM!  You had to pull the carbs and airbox TWICE!!>>???  Man, I did it about 4 times last year swapping carbs until I found a good set...  

Glad you got it fixed.  That, I have never heard of.  I have 113k on Ole Blue.  I will have to keep an eye on that.  $28 for the housing, not too bad and easier to install than those O-rings!

Thanks...

Hay  
Jimmyt

[Punisher]

Based on that seam/crack being inline with that bolt hole it is feasible that it was overtightened at some point (even at the factory) and started that hairline crack.

Just goes to show the toughness of these ole girls, ran over 200k miles before it failed enough to be noticed. 

[Jess from VA]

It sure looks like a part that should be aluminum and not plastic, but with only one (this one) noted failure, who knows?

Thanks for the write up Jeff. 

As our old gals continue to age, new and exiting discoveries may be on the horizon.  (Bikes, not wives  )

[Chrisj CMA]

Based on that seam/crack being inline with that bolt hole it is feasible that it was overtightened at some point (even at the factory) and started that hairline crack.

Just goes to show the toughness of these ole girls, ran over 200k miles before it failed enough to be noticed. 

Not likely that over tightening was the culpret..First  because I was the one that removed the bolts and they were not that tight. and secondly there are metal sleeves in the holes that would prevent the pressure of the bolt from over stressing the plastic.

[Punisher]

Does the crack run over to the metal sleeve?   Hard for me to tell in that pic.

Do those sleeves seem to be a press fit when manufactured?  Perhaps it was pressed in slightly crooked and cracked it?

First one of these I've ever heard of, usually always seems to be that hose clamp needs tightening.

I agree, in the next few years we'll be seeing all kinds of new things needing maintenance, like those water pipes underneath that have o-rings on them.

Good work Chris 

[saab9k]

I bought a universal radiator pressure kit, wash everything clean, apply 14- 15 lbs pressure.
Do that with every oil change I do on my car and truck. Will do that on Valkyrie too.
Or when I see fluid drips.
My Yamaha road Star 1700 trike is air cooled.

Harbour freight around $50.  with adaptors to fit different makes.

[old2soon]

THAT was a good catch.  AND the reason this board wurx as well as it do.  Sahring these valuable bits of information as we run up on them.  Again-good catch. RIDE SAFE.

[wiggydotcom]

Thanks for sharing your find with the rest of us, Jeff.
Another page to the chapter that's part of our VRCC book, "How to Keep the Dragon Alive". 

[olddog1946]

Thanks for sharing your find with the rest of us, Jeff.
Another page to the chapter that's part of our VRCC book, "How to Keep the Dragon Alive". 

10-4 on that.....most likely be seeing some new stuff in the coming years.

[Chrisj CMA]

Does the crack run over to the metal sleeve?   Hard for me to tell in that pic.

Do those sleeves seem to be a press fit when manufactured?  Perhaps it was pressed in slightly crooked and cracked it?

Yes the crack went right to the sleeve.  Sleeve looked good, Id have to say this was just age.  Plastic, aluminum, steel.........age plus hot, cold, hot cold with pressure, a part or three are bound to fail eventually.

[Brovietnam]

My '97 appears to be leaking at this time.  Perhaps this could be the reason.  Thanks for the heads up!