Coolant in Transmission Oil

CPERRy

Member
Recently cahnged the oil in my 04 crf 450 and the oil was battleship gray (milky). THe bike was running hot and losing coolant.

Has anyone ever heard of coolant in the tranny? Possible fix? :whoa:
 

76GMC1500

Uhhh...
When was the last time you changed the oil? Again, it's probably clutch debris, perfectly normal. Change the transmission oil often. The coolant loss is probably a seperate issue. If no external leaks are visible and it is not getting into the engine oil, it's generally a head gasket.
 

Shad 250

Member
Coolant in the tranny oil usually is caused by an inner water pump seal that has gone bad. This is pretty common on the Honda 450's. I would check there.
 


trial_07

Play with gravity
Yes, replace the water pump seals and see how it goes.
 

76GMC1500

Uhhh...
There is nothing misguided about my post. A lot of people come on this forum thinking they have coolant in the transmission oil when it's really clutch debris. Battleship gray is the color of oil with clutch debris. Oil with water in it is generally a bit more brown. It's hard to diagnose problems over the internet. A picture would really help.

Though, I do admit I have heard of a lot of water pump seal failures on teh CRF450's
 


oldguy

Always Broken
76GMC1500 said:
There is nothing misguided about my post. A lot of people come on this forum thinking they have coolant in the transmission oil when it's really clutch debris. Battleship gray is the color of oil with clutch debris. Oil with water in it is generally a bit more brown. It's hard to diagnose problems over the internet. A picture would really help.

Though, I do admit I have heard of a lot of water pump seal failures on teh CRF450's
Yes there is a problem when you jump in and give what you expect to be taken as expert advice which is no where close to the problem. Sometimes it is better to sit back and wait for someone with actual experience on that bike to chime in.
 

76GMC1500

Uhhh...
Is there no weephole between the water pump seals? If the water pump seals were leaking, wouldn't there be water coming out there? Or, is it just the o-ring in the right side cover gasket that is leaking and the water pump seals are fine?
 

Ol'89r

Member
CPERRy said:
Recently cahnged the oil in my 04 crf 450 and the oil was battleship gray (milky). QUOTE]


The key word here is (milky). That would indicate a bad inner water pump seal.

What o-ring on the right case gasket are you referring to GMC?
 


76GMC1500

Uhhh...
Instead of going through a hose to the cylinder, the water pump discharge on the early 90's up CR's and all CRF's goes through the right side cover, through the cases, to the cylinder if I'm not mistaken. There is an o-ring between the right side cover and crankcase that seals the passage. If this o-ring were damaged, that would explain water in the crankcase without water coming out of the weephole between the water pump shaft seals.
 

Ol'89r

Member
If you are referring to the o-ring that goes around the little metal collar between the side case and main case, yes it could leak. But, it is highly unlikely since it also has the gasket to seal it. The o-ring would almost have to be missing for it to leak. I have never seen one deteriorate other than harden.

Unless he had the side cover off and left the o-ring out, the most obvious place to look would be the inside water pump seal.
 

john stu

Lifetime Sponsor
in eric gorr's book he says to replace the seals,shaft and the shaft bearing when the seals fail something about the design of the bike and the bearing needing replacement because of it surporting the shaft on one side only
 


CPERRy

Member
Thanks!

I have had fluid coming out the weep hole and have replaced the outer water pump seal. My understanding is there are two seals and inbetween the seals is the weep hole.

If coolant is making into the tranny oil, does that mean I have to rplace the inner seal? I would assume if the innerseal were bad I would be losing tranny oil?....

I think the water pump shaft maybe defective, being that I've had to rplace the water pump seal twice and I don't have alot of hours and I don't ride the bike that hard...

Thanks for all your help!!!! :cool:
 

Ol'89r

Member
CPERRy said:
I think the water pump shaft maybe defective, being that I've had to rplace the water pump seal twice and I don't have alot of hours and I don't ride the bike that hard...
:

When you remove your water pump seals and shaft, look at the shaft and you will probably see a wear groove on it. The seal will wear a groove into the shaft and the new seal will ride in that groove and not seal as well as it should.

It's best to replace both seals, bearings and the shaft. The cost of all those parts is miniscule compared to the damage that can be caused by overheating your engine.