Primary Leak!

[slowrower]

If you find yourself with a leaking primary cover first thing to check is the Primary Case Vent which is easy to get at with a 7/16" wrench (be carefull as some are nylon). A friend had a small leak in his primary and after installing a new clutch and cable I also removed the primary vent which was plugged solid .. I suspect this was causing the leak as pressure built up it had no where to go but out of the primary cover .. THIS CAN ALSO force oil into your starter. Be sure to check it!! The vent hole is tiny and it won't take much clutch material bonded to oil to block it!

 

[Fibersnake]

slowrower,

Good point and maybe a point on some of the leakage. May even be more agravated if one had plugged off the vent on the inspection cover area with say RTV or something.

 

[BubbleHead]

anyone have a picture of exactly where this vent is located?

 

[Fibersnake]

BigBlue,

The one I was refering to is on the groove for the O-ring on the inspection cover. It is a little notch between the inner O-Ring and outer O-Ring that allows some venting through the foam piece (breather filter) and the atomosphere.

If you put the O-Rings on without RTV, it will allow it to breath, however due to being a PITA with the O-Ring getting pinched, especially if using an old one, many, include dealers will install with Gray RTV to hold in place.

There is also a vent hole on back side of inner primary a little higher, that allows for venting. The one on back side may be more for fail safe, not sure. It is located between engine and tranny and is up near top. Looks sort of like a nut but with a wire screen in center to allow for vent.

What I can say is that initially I would try to re-use my O-Ring on the primary cover and it seemed like I got more leakage. The last couple of times, I just buy all the O-Rings including the outer primary cover one, drain the cover, pull it, clean it all up and inspect, adjust the chain, put new O-ring on with out RTV, tighten to specs, then same for inspectins cover, fill with 32oz Rev Tech Primary fluid and go on my way.

No leakage whatsoever since I have started doing that. Occasional very fine sheen near inspections cover from venting, does not even get enough to require wiping off to prevent a drip, though I do anyway. Also such mainly shows up when I have put on a few hundred miles or more.

 

[BubbleHead]

Fiber, my inspection center cover has a flat rectangular gasket that seals it from leaking. It doesn't use an o-ring. Now the larger round one in the rear of the outer primary might or even the smaller front round cover. Never had them or the outer primary cover off. Just the rectangular one in the center to re-fill the fluid with or adjust the primary chain tension.

 

[Gas Man]

Fiber, my inspection center cover has a flat rectangular gasket that seals it from leaking. It doesn't use an o-ring. Now the larger round one in the rear of the outer primary might or even the smaller front round cover. Never had them or the outer primary cover off. Just the rectangular one in the center to re-fill the fluid with or adjust the primary chain tension.

BBD that is the update to their dumb venting idea on the inspection cover.

The original idea was that the insp cover would be the vent. That there was no way the fluid would travel upwards thru the square void from the lower left corner, thru the sponge that was suppose to be there, to the channel above (mine is already sealed with silicone in pic below), across the top channel, and out of that cover area. WRONG! So they started to have techs seal that venting setup with silicone, sense you had the button on the backside of the inner primary. Then they went to the one piece large square gasket instead of this o-ring setup.

The vent like I said is on the backside of the inner primary between the motor and the tranny. Smaller than a dime and has a mesh center to it. You can see it on the inside in the pic below... at the top above the adjustor

Here you can see it to the right of the shifter arm on the tranny and under the shifter linkage

But this thread brings up a idea that could be a potential reason for so many starter leaks. Maybe that should be part of the maintance of the primary... remove and clean.

 

[BubbleHead]

Gas as usual your response is awesome. So I assume that means I don't need to worry any about a vent in my inspection cover by using the flat gasket. Without going out to my dog, the only way to clean the backside vent is to remove the outer primary cover, Yes? If so how often would you say that should be done?

 

[gooddoggie]

When I took my 05 chopper in to the dealer to fix this problem I did not have an inner primary vent hole on my 05 but he drilled a hole and installed a mesh screen so I suspect the older models did not have this but were only vented through the center front primary inspection cover, which did leak on mine also. I also put a generous amount of silicone seal on it when I changed my primary fluid and probably did close it off but have had no leaking problems since as the new inner primary vent hole now serves this purpose very well

 

[slowrower]

The 2006 Mastiff and my 2007 had full gaskets on the inspection cover so they were sealed which is why the vent on the backside of the primary is necessary. Just be sure to clean once in a while or like Superfly it will find a way to relieve the pressure and that means your primary cover will leak or worse it will get into your starter.

 

[superfly]

does this vent have a one way valve?

 

[slowrower]

Good thought, may release at a certain pressure to the outside.

 

[JoshT]

I am also having a slight leak from my primary. Its seems to be running down the backside of the primary and dripping by the drain plug. I know for sure that it is not the plug itself and cannot seem to find where it is coming from. Also my belt seems to be getting a bit of oil on it as well. Probly coming from the same area. Any help or suggestions would be greatly accepted...

 

[delly2]

so do you have to remove the primary cover and oil to do this? and how do we know for sure this will stop the starter leak and not cause any other problems,dont ya think bdm would have figured this out before replacing starters on bikes that were leaking? and even if you get a new starter wouldnt it eventually start leaking again??

 

[reloaderbmg]

so do you have to remove the primary cover and oil to do this? and how do we know for sure this will stop the starter leak and not cause any other problems,dont ya think bdm would have figured this out before replacing starters on bikes that were leaking? and even if you get a new starter wouldnt it eventually start leaking again??

IF thay did not update the starter "yes it would!"

 

[Fibersnake]

GasMan

I understand about the sealing with the RTV and the flat gasket, however I still have my original type, the filter screen and do not use RTV. It has worked fine and no issues. They still sell the O-Ring also. Can not speak for others, just that mine is working as designed orginally. May be lucky or different set-up than others.

 

[delly2]

fiber, it seems like the kit is more then a oring,are you familar with this kit and have you installed it yourself? the way fullhouse explained it ,its not an easy task,and its more then a oring,it has nuts,springs,bearings,gasket,etc.. jim

 

[Fibersnake]

delly,

No I have not installed one myself, and yes I talk to them and they said was not the easiest thing to be done. I have no leak myself, but just trying to help others out. The way I understood it, it will take some work and but could be done by most with the proper tools. I also know that they said they could do it for anyone if they wanted to send them the starter.

Also it should be something that any good starter repai shop should be able to do quick and easy along with most mechanical shop. For a good part of the folks on here, it would not be too hard either, but yes, from my undertanding it is not a simple pull off starter throw a seal in and re-install.

Still, if it does the job, has to be better than spending a few hundred dollars on replacing one.

Good luck!

 

[Gas Man]

BBD... No, if you look at the button screen, it screws in I believe... if somebody reminds me I'll check my old primary when I get home.

Superfly... I don't believe it has any type of check vlv, I think that is just over thinking it.

Josh, it sounds like you have a starter leak... very common and delly has about 3 threads on his.

Fiber, yours is one of the few. Most remove the filter screen (think of a sponge) from under the inspection cover and as gooddoggie said, installed the button vent.

The end all BEST option is to go with an open belt.

 

[Fibersnake]

GasMan,

You may very well be right on me being one of the few with the filter screen. I will say it does also have the button screen on the back and maybe between the two may be why.

On a personal item, hate to see RTV on any pre-formed gaskets (i.e. O-ring)-goes back to my background. A proper designed o-ring is supposed to seal due to compression and expansion, generally if it does not, it is due to improper gasket, bad sealing surfaces or poor design, or improper torque.

That said, I know that it is used all the time and any many cases it is the only thing that will stop the leak. Just something about haivng to put a flat gasket with sealer over a machined groove that was designed for a pre-formed seal. Oh and yes my dealer has even used RTV to help hold it in place! Go figure.

 

[superfly]

this little valve must really keep the fluid from coming out. Slowrower and I just finished up my clutch yesterday. I was putting the vent screen back on and while screwing it back in it broke off. I thought no biggie will get a new one and tap the old thread back out next week. Drove home and about half way home I was leaking primary fluid like a siv. Every traffic light I was leaving little puddles. Got it home put some paper down on floor and as it cooled it continued to leak out of the hole until my garage floor looks like a crime scene. How could that little vent make that much difference? i'm baffled