Topped up transmission fluid; hissing and steaming.

[Mark Friedman]

This is my first post. I've read the rules, but excuse any transgressions from this newby. Added transmission fluid at the proper level, added new crush washer torqued the bolt properly. Took my '92 K75 this AM for a spin headed for the lovely Catskill Mountains of New York, Couldn't have run better. Covered about 3 miles. Curious smell at stoplight, and hey, OMG (as my daughter would text), sulfurous steam rising from somewhere beneath the gas tank. Cautiously rode it home in fear, loathing, ignorance and frustration. Looks like leaked transmission fluid was the culprit, hitting the exhaust and steaming up. But from where?  And why would this happen immediately after a top-up? If it's the seals, why would they fail immediately after a top-up? (Doesn't seem to leak when engine's running on center stand--even at higher RPMs. Leaks when riding. Might someone of a higher order of intelligence answer this for me? Many Thanks.

[kioolt]

How much did you add when you topped it up?  Do you have the proper tool for measuring the correct level?  In over 400k miles of owning BMW's I've never added oil to the transmission between changes.  If it's not leaking there's no reason to add oil.

[K1300S]

Yes.   Define top up and proper level.

[Mark Friedman]

Hellow miytle I used "top up" in reference to adding more transmission fluid. The tool was (in layman's terms), the rear shock adjusting wrench which has an indicator line on the handle about 3/4" above the bottom of the handle.

[Chaos]

tool should look like this...

[Mark Friedman]

Yes, this was the tool I used.

[K1300S]

Sure it is Trans oil and not engine oil?  Can you follow the leak to its source?

[TimTyler]

Why did you need to top it off? How low was it before topping off? When was it last at the proper level?

[The Mighty Gryphon]

Coming up from under the tank?   Are you sure you didn't have a coolant leak???

Did you do a recent top up of the cooling system?  I would expect a boil over from an air bubble before a massive trans leak.  The overflow tank and the hoses is where I would look first.   Is there oil all over the place?

[kennybobby]

When i took the red 75S for the first ride after trucking it home, the rear wheel got douched in oil from jenner fluid leaking out of the vent--previous owner had filled it to the brim.  Don't recall it causing any smoking.

[Mark Friedman]

I'll check to see if it isn't a motor oil leak. Odd that it would happen just after I added transmission fluid.

[Mark Friedman]

replies to more questions:

I added transmission fluid because things sounded a little funny down there during idle and it turned out trans fluid was quite low. Needed about 3/4 qt. before it came up to the line on the tool.  After adding the stuff, the sound went away and everything seemed to be running very smoothly.

[kennybobby]

Sulferous steam => battery vent tube overflow runs right down onto the exhaust

Maybe voltage regulator not working and overcharging the battery.

[Chaos]

Transmission only holds about a quart.  I you had to add 3/4 qt there must be a leak somewhere, i'd check if the level is down again then figure out where it's leaking from.  Could be leaking into the bellhousing or the shaft housing, would not be obvious right away. 

[Mark Friedman]

Thanks all...will check battery and transmission for leaks.

[Martin]

Thoroughly clean and dry the engine & transmission and anywhere else you think it could be leaking. Put the bike on it's centre stand and check your fluid levels in the engine and coolant. Run the engine and check for leaks, you can use spray Talc on parts to show up the leak better.
Regards Martin.

[K1300S]

Super dumb question but. ....

When you filled it....it was on the center stand, right?

[Mark Friedman]

I had the bike on its center stand when I filled it. Will check for leaks.  Thanks everyone for your invaluable help.

[rbm]

If it was overfilled, the excess might exit the vent on the top of the gearbox, just by the starter motor.  You'd notice a dribble of oil from the top and down the left side.  If the gearbox is to leak, it will do so from the input shaft seal or the clutch pushrod boot, neither of which are near the exhaust.  There might be the off chance oil is leaking out from the gear shift lever shaft but I've never heard of that before.

Engine oil will not give a sulphurous odor.  Could be the battery overflow, as mentioned above, if you have the OEM flooded cell battery.

[TrueAce]

Simply put, the steaming, hissing fluid was excess transmission fluid.........either you over-filled and the excess vented out, or you tipped the bike over causing fluid to spill out. Just make sure you have the correct amount next time. The spilled fluid will burn off.

[Mark Friedman]

Thanks. That's a nicer scenario than having to pull the transmission.

[TrueAce]

I have experienced the tip over, gentle, lay down. Then rode a few miles until the first stop light, scared me with all the stink & steam. Check your fluid again, ride it until the exhaust burns off the spill. Report back. If it is any other fluid or if it continues, take pictures and post.

[The Mighty Gryphon]

It would be really cool if you could tell us what the engine and transmission oil levels are after the "leakage". 

Also, if there was enough oil leaking to be getting on the exhaust, I would expect there to be oil all over the left side of the engine or transmission.  Could you please tell us if you can see any there.  That is one piece of information you have yet to give us in any of your posts so far.

[Mark Friedman]

I believe I've solved the problem (or maybe not) by once again testing the transmission fluid level with the proper tool--something I'd done before. But, I didn't plunge the tool far down enough. I needed to move it further back in the hole, and when I did, the tool sunk down and indicated I have way too much fluid. I hope I didn't do some damage as a result! I'm going to drain the fluid to the proper leve and see. If everything's alright, I will offer up a sacrifice to the Wrench Gods. Many thanks.