Topic: Violent oil leakage from filter housing

[ekpent]

 So it looks like then its not a simple gasket/o-ring problem around the filter. Hmmm

[754]

Is thrte a crack,  gouge, or scrape on the surface where filter housing sits ?
 Does filter housing have any cracks,  wipe clean lookaround area where the bolt passes thru.. 

[BenelliSEI]

The filter housing has a tab that fits between two centring “fins”, when mounted. Do you have it right side up and the tab located correctly?

The stock centre bolt typically has a 12mm hex (for the wrench). Is your original? Some aftermarket parts  have 14mm and 17mm heads. If the threads are not cut correctly, it may not fully tighten. Do you think yours is original? After that, I’m out of ideas. Post some pictures showing the install and indicating the leak.....

[ekpent]

Have you noticed what part or area of the filter its violently leaking from like around the area where it fits flush with the engine or another place. You do have the smaller o-ring around the bolt I hope in the groove close to the head where it seals with the housing.

[scbotanist]

Is thrte a crack,  gouge, or scrape on the surface where filter housing sits ?
 Does filter housing have any cracks,  wipe clean lookaround area where the bolt passes thru..

I can't find anything on the filter housing or engine block that looks like it could be causing this leak. There are some very minor hairline cracks on the housing where the bolt runs through (which admittedly I have slightly worsened over this whole process by overtensioning the bolt), but given that the leak is coming from from where the housing mates with the block, I don't think they'd be causing the issue. I'm going to try again and film it this time to give folks a better idea of what I'm working with.

The filter housing has a tab that fits between two centring %u201Cfins%u201D, when mounted. Do you have it right side up and the tab located correctly?

The stock centre bolt typically has a 12mm hex (for the wrench). Is your original? Some aftermarket parts  have 14mm and 17mm heads. If the threads are not cut correctly, it may not fully tighten. Do you think yours is original? After that, I%u2019m out of ideas. Post some pictures showing the install and indicating the leak.....

Right side up and centered every time. The bolt that I'm currently using has a 12mm head. I got it and the housing from a friend who restores Hondas and had some spares, so I'd guess that they're probably original. The bolt that was with the housing that had the initial catastrophic failure had a 17mm head though...maybe the threads on that bolt were not correctly cut, and caused some degree of stripping on the threads in the block...I might try swapping that bolt into the new housing I'm using and see how that goes.

Have you noticed what part or area of the filter its violently leaking from like around the area where it fits flush with the engine or another place. You do have the smaller o-ring around the bolt I hope in the groove close to the head where it seals with the housing.

Yes, definitely have the smaller o-ring on the bolt. The leak tends to spring from the 4-6 o'clock position if you're looking at the bike straight on, but I don't see anything on the housing or block in that area that would indicate the possibility of a failure.

[754]

Well, if you see cracks in the housing try another housing ..
 I can image that crack widening as you tighten up the bolt..even a light amount if torque.

[scbotanist]

Well, if you see cracks in the housing try another housing ..
 I can image that crack widening as you tighten up the bolt..even a light amount if torque.

I'm planning on getting a new housing to try out, but given that the cracks were miniscule to nonexistent when I first started using this housing, I don't think they're the source of my current issue. I'm sure it's only a matter of time until they lead to the same fate that my first housing suffered though.

[scottly]

Please post some pictures using the attachment option.

[scottly]

I did an oil change to get it running smoother for a compression test and carb sync, but when I replaced the oil filter housing with a new filter, the housing exploded on me.

Do you mean it really exploded, throwing oily filter housing shrapnel?

[ekpent]

 One thing I would check is that the breather and its hose that runs out the back at the top of the valve cover is clear and not blocked. I did a 750 once and member Sean was the lucky guy to take it for the very first ride.  Came back after a shorty with the rear of the bike covered in oil. Long story short some kind of a wasp or other critter had built a nest and plugged the rubber vent hose very well building pressure in the engine/oil tank. Little carb cleaner and a blow with an air hose fixed it right up after cleaning up all the oil 

[seanbarney41]

I had this happen with a newly rebuilt kz1000 engine, which was weird, because they don't make oil pressure the way an sohc4 does, due to a roller bearing crank versus plain bearing.  But anyway, all I could find was that the oil filter I had was maybe a 16th of an inch too long.  I got a different filter and all was good.

[scottly]

A too long oil filter that prevented the housing from sealing against the case would cause a leak, but with the spring I can't see that happening with an SOHC?

[scbotanist]

Well, go figure, as soon as I set the camera up to record the failure, it fails to occur. It looks like the addition of the spring and washer may have been the solution I was after all along. I can't say why it didn't work the first time around with them in place.

When I was comparing the two filter bolts I have, I noticed the (aftermarket) O-ring on the 12mm head bolt that I'm using is pretty skimpy compared to the one that is on the old bolt. I think that combined with the cracks in the housing are the causes of the minor leakage from the bolt seen in the video. I'll set about switching the old o-ring over as soon as I'm finished diagnosing and fixing the cylinder(s) not firing.

I did an oil change to get it running smoother for a compression test and carb sync, but when I replaced the oil filter housing with a new filter, the housing exploded on me.

Do you mean it really exploded, throwing oily filter housing shrapnel?

Perhaps exploded isn't quite the right term, but catastrophic failure is certainly accurate. See photos 1 and 2 below. Other photos are hairline cracks in new housing, engine block, old and new filter bolts.

[scottly]

In the video I can see the oil leaking from under the head of the bolt. The only way the cracks in the housing could have happened that I can think of is the bolt was WAY over-tightened?? 

[754]

3 cracks on that one HAS TO LEAK....
 I was cleaning up a very nice chromed one to put on my bike, saw same thing.. did not use it..

[scbotanist]

3 cracks on that one HAS TO LEAK....
 I was cleaning up a very nice chromed one to put on my bike, saw same thing.. did not use it..

In the video I can see the oil leaking from under the head of the bolt. The only way the cracks in the housing could have happened that I can think of is the bolt was WAY over-tightened??

In my naievete in attempting to fix the issue, I'm sure I definitely overtightened the bolt on more than one occasion (tighter bolt means tighter seal means no leak right?? wrong). Knowing the spring was the issue makes me feel comfortable buying another replacement housing and hopefully closing the book on this particular problem.

[PeWe]

The correctly sized O-ring must not be tightened too much. Maybe same force as when tighten an M6 without damage

Cracking a cover is above max for M12-14 too?
That's way too much several times!

There is a risk with new aftermarket oil bolts with 17mm head. Honda used 12mm by a reason.

[BenelliSEI]

Also note the threads are short on the locating bolt it’s 17mm HD head. They don’t go up the shank as much as the 12mm. Use the 12mm. What torque are you using on the bolt? It needs very little.