Milky Tranny Fluid - my problem finally solved - may help someone

[DaveH]

Had been suffering with the milky tranny fluid problem for almost twelve months. Always evidence of water ingress inside the RHS power valve chamber.

Had almost gone blind looking through threads on the subject & changed water pump seal three times, put in new water pump shaft, re routed breather hose to frame etc with no joy.

Was resigned to changing oil after each ride and just got on with riding it.

Took it for an annual MOT test and noticed during the test it had puked a bit of coolant out of the overflow pipe...it had never done this before...(neither had there ever been much evidence of the expansion tank being filled/emptied during a ride)

Fitted new radiator cap...bloody hell...been perfect now for three very long, technical & wet rides.

Assuming the system was over pressurising and pushing water past the water pump seal/splashing up through PV actuator rod hole. Cant understand why there was never much coolant evident in the expansion tank though.

With the new cap the expansion tank is working as it should.

If your at your wits end and tried everything else its worth a shot for what it costs to replace.

 

[wence]

Good find mate, Thanks for posting.

 

[19brendan81]

Its amazing how often a faulty cooling system in a bike or car comes down to something as simple as a radiator cap. Thanks for sharing.

 

[HuskyDude]

Good find..Thx for posting.

 

[(F5)]

Ha! I just searched under rad cap as I was forming that theory. Here's the proof I need that it is worth trying. Another impeller seal is on way now, but what the heck. Thanks mate.

 

[twowheels]

Well played! You might want to upgrade your existing cap with one range higher as well. 2010s with expansion tank had 1.4 bar; 2011s with essentially the same rads and water pump has cap rated at 1.8 bar.

 

[husley]

Hmm

I have also heard of a non-properly functioning system pulling tranny oil into the cooling system when the bike is cooling down.

I had tranny oil in my coolant but turned out to be a loose impeller bolt

 

[(F5)]

Also the impeller seal needs the correct preload I am told. I'll do both for the weekend.

Been told to flush box with diesel of all things to absorb the water & even start it on the stand for a couple of min & reflush, then run a cheap oil for a ride & then back to decent stuff.

 

[blitz11]

Kerosene was a trick taught to me by my dad. In WWII, he was a fighter aircraft mechanic on Guam. After an engine rebuild done under less than ideal conditions, they'd fill the oil system (dry sump) with kerosene, run the engine for about a minute, then drain the kerosene, and then refill with motor oil. Flushed all of the nasties out. Apparently, made a difference in engine longevity (for the better).

 

[(F5)]

yeah I had flushed with Kero, but not run it. Diesel apparently is good for mopping up the water.

I might pour some of the remainder down the sparkplug holes of my mate's still seized RD350 in my lockup & try kicking it in a couple of months. Supposed to be the biz for that if left, more so that penetrating oil which I've tried.

 

[(F5)]

So just a question for the Original poster as I re read your post; Does your model have a tank recovery system? All the GasGas I have seen don't use the expansion tank in this manner. The tank is connected to the radiators without the cap in the way.

 

[sevenfourate]

So just a question for the Original poster as I re read your post; Does your model have a tank recovery system? All the GasGas I have seen don't use the expansion tank in this manner. The tank is connected to the radiators without the cap in the way.

Old topic revived warning !

Oil change, filter clean, chain adjustment etc today, along with checking coolant level.

My 2006 EC250 has no expansion tank, but i know my friends 2005 EC300 does (Upfront around the headstock.) Im pretty sure that although mine has no tank - the fixing lug / bracket is there......

Is it previous owners removed who have them, or do some do and some dont from the factory ?

 

[gasgasman]

The expansion tank is not a necessity.
Just fill the radiators a 1/4 inch above the cooling passages, there's enough area in the radiator tanks to allow for coolant expansion.