Ducati.ms - The Ultimate Ducati Forum banner

1 - 11 of 11 Posts

·
Premium Member
Joined
·
249 Posts
Discussion Starter #1
The following photos are from my 1998 ST2. The area in question in the photo is clean of oil as I cleaned it off. But, I think/am pretty certain that my oil leak is coming from this area. Anyone know what this is called for certain and how big of a deal it may be to fix it? I believe this is the overfill port/valve. But my oil level is not over the max line. And it seems that the leaking only occurs when I use the sidestand.

Input anyone? Thanks.


 

·
unM0derator
Joined
·
2,853 Posts
You're indicating that the leak is coming from the crankcase breather. There is no o-ring gasket under the valve (according to the parts diagram).

Do you see any oil on the back and bottom of the vertical cylinder?
 

·
Premium Member
Joined
·
249 Posts
Discussion Starter #3
On the first image I have seen oil sitting on top of the black rubber piece as well as below the silver band. The oil will form a small pool on the left side of the bike on the engine case in front of/above the front sprocket area. So yes, on the left hand side behind the vertical cylinder.

Discussing this over the phone with a local mechanic he said something about replacing the breather with a newer model's. Granted, he diagnosed this over the phone but I think he's on the right track, as that is where I can see some oil forming. I have been keeping a very watchful eye to see were oil might be leaking from. This is the only area I can seem to identify as of yet.

I rode about 100 miles today and only saw a tiny bit of oil on the top of this piece. I used both the side and center stand but could not duplicate the leak I saw during my recent trip. Would riding for say 300 miles at speed create a more noticeable leak perhaps?

Hope I answered what you are asking. Let me know if not and I will try to explain better.
 

·
unM0derator
Joined
·
2,853 Posts
The purpose of the breather is to eliminate blow-by gasses from combustion that get into the crankcase. The breather feeds these gasses through a one-way valve and a tube back into the airbox where it can be ingested and burned. Some oil will always be present in the mixture that comes out of the breather.

If there isn't a tight seal, then yes, you can have an oil coating from the escaping gasses. Changing the breather valve and tubing is pretty cheap and will eliminate that as a potential problem.

Should there be oil at the rear of the vertical cylinder nearly at the mating of the jug to the case, then that may be an indication of the cylinder (not head) gasket failing.
 

·
Premium Member
Joined
·
249 Posts
Discussion Starter #5
Well, I've only seen oiling pool when the side stand has been in use. Leading me to believe that I may not really have a big issue-I will hope... Seems that from what you have said, along with a mechanic over the phone that if the breather is leaking and I keep the bike on the center stand I wouldn't see any oil pooling. On the side stand, gravity takes over and the oil winds up where I stated. Makes sense, and I will go with that for now and have it looked at further when I get it serviced in about 2,000 miles. Meanwhile, a watchful eye on the oil just in case.

Thanks for your input. I hope I don't have a cylinder leak. Sounds expensive...
 

·
Registered
Joined
·
3,883 Posts
That's the crappy style breather. My 1998 had the same one, with the Al. band around it. It's a crappy design, because it's a 2 piece unit, held together by the band. All the old style ones leak. The newer ones are 1 piece, and have an o'ring integrated into where it seats to the crankcase. Newer ones don't leak.

Keep your eyes on eBay, or here (place a WTB ad for a newer one.) Many gents/ladies "upgrade" their's with machined aluminum aftermarket ones. Ya know, the pink anodized ones, or black, yellow, gold, or plain Al. They're about 80 or 90 bucks from various places. I bet even a newer Ducati one might be cheaper than these bling units, and as I said, the newer ones don't leak.
 

·
Registered
Joined
·
191 Posts
Mine leaks too, not too much oil, but it's always wet on top of the breather. I'll replace it first thing... next year.
 

·
Registered
Joined
·
1,246 Posts
Mine leaked to - not too much more of a dampness than a pool.

Dealer told me it is a known issue and there is a newer version (as before). Mine looked like it was going at the seal so I took it off and applied a little gasket seal and replaced it. So far so good
 

·
Mr Leakered
Joined
·
8,815 Posts
You may want to do a search on that breather mod. Eliminating the tank will drop power. Supposedly the Corse bikes use an even larger volume tank under the seat. It increases the effective volume of your crankcase, esp with the vacuum created in the airbox.

That and the possibility of oil blowing out the K&N breather under very hard acceleration.

Have a good one.
 

·
Premium Member
Joined
·
249 Posts
Discussion Starter #11
Thanks for all the info. For some odd reason, since I was at the shop when it leaked, I have not leaked oil since. Only a tiny amount of pooling oil on the breather. Note enough to even leak to drip.

A few guesses. First, maybe it becomes more notable after riding for 6 or more hours? Second, the shop left the bike on the side stand overnight. Something I don't do normally?

We shall see what happens. My oil level is never past the max mark hot or cold so i don't think I have too much oil. And my overall oil loss has been extremely minimal.

Intermittent oil leak?
 
1 - 11 of 11 Posts
Top