Enots Oil tank cap leaking

Joined
Oct 27, 2022
Messages
27
Country flag
Hi,

i'm riding around with a Minnovation Oil tank with "Enots Birmingham" cap. On longer rides, there's always a bit of oil leaking around the cap. And the oil is definitely searching for my rear tyre! ☹️

I have inspected the gasket and it seems to sit very neatly on top of the rim of the enclosure. Also i turned the tank around earlier, the oil is leaking from the gasket area (not from the thread that locks the cap to the tank). After taking things apart and reassembling, same problem...

I've checked other topics here, and it seems like most stock commandos have cork gaskets, also i found a link to "realgaskets" which might become helpful..

But for now: does one of you have experience with this particular Enots cap? Maybe i have assembled the spring mechanism inside the cap wrong?

Thank you!!

PS: Excuse the cat hairs...

Enots Oil tank cap leaking
Enots Oil tank cap leaking
 
Not sure from the photo, but it appears your tank vent line runs from the cap above the gasket. If there is not a an unobstructed path to this vent then pressure will have to blow though the seal, no matter how good.
Can you blow, with your breath, through that hole in the copper retaining plate? If not, I suspect that will be your problem.
Cheers
 
Hi,

i'm riding around with a Minnovation Oil tank with "Enots Birmingham" cap. On longer rides, there's always a bit of oil leaking around the cap. And the oil is definitely searching for my rear tyre! ☹️

I have inspected the gasket and it seems to sit very neatly on top of the rim of the enclosure. Also i turned the tank around earlier, the oil is leaking from the gasket area (not from the thread that locks the cap to the tank). After taking things apart and reassembling, same problem...

I've checked other topics here, and it seems like most stock commandos have cork gaskets, also i found a link to "realgaskets" which might become helpful..

But for now: does one of you have experience with this particular Enots cap? Maybe i have assembled the spring mechanism inside the cap wrong?

Thank you!!

PS: Excuse the cat hairs...

Enots Oil tank cap leaking
Enots Oil tank cap leaking
From the photos it looks like the seal isn't fully seated. Perhaps the cap needs a stronger spring and or if it's possible adjust the small nut to move seal and brass support washer near to the tank neck locking it with a spacer or thread lock to prevent it unscrewing?
 
Did the tank come from the makers with the cap already attached? The Enots cap i have in my hand has a fine screw thread to attach it to the intended tank. The trick to get the cap aligned was to ignore the fine thread and glue the cap onto a welded stub on the tank, Easier and cheaper and quicker than screwcutting a stub to then weld onto the tank. Your oil leak could be getting out there...
 
Did the tank come from the makers with the cap already attached? The Enots cap i have in my hand has a fine screw thread to attach it to the intended tank. The trick to get the cap aligned was to ignore the fine thread and glue the cap onto a welded stub on the tank, Easier and cheaper and quicker than screwcutting a stub to then weld onto the tank. Your oil leak could be getting out there...
Yes the tank came with this cap on there. It has the fine thread as well, but it sits real snug, doesn't want to spin at all. The leak seemst to be coming from the gasket surface.
 
Not sure from the photo, but it appears your tank vent line runs from the cap above the gasket. If there is not a an unobstructed path to this vent then pressure will have to blow though the seal, no matter how good.
Can you blow, with your breath, through that hole in the copper retaining plate? If not, I suspect that will be your problem.
Cheers
Actually there is a seperate atmospheric pressure valve behind the cap, so that should not be the problem.
 
From the photos it looks like the seal isn't fully seated. Perhaps the cap needs a stronger spring and or if it's possible adjust the small nut to move seal and brass support washer near to the tank neck locking it with a spacer or thread lock to prevent it unscrewing?
I'll have a look at a stronger spring :) the gasket looks so clean, same as the surface it seals on, that's why my leakage is so surprising...

Thank you all for your help!!
 
Its either getting past the gasket/cap or getting past the thread. If you can, rig up a temporary blank to seal onto the sealing face of the mounting ring. That is if your tank is vented elsewhere other than the cap. Go for a ride and see if it leaks again. If so, it is the thread leaking.
If not, its the cap gasket.
If the tank vent is through the cap and piped up to a catch tank etc you will have to rig up a temporary vent through the blank.
What is this 'atmospheric pressure valve'?
 
Its either getting past the gasket/cap or getting past the thread. If you can, rig up a temporary blank to seal onto the sealing face of the mounting ring. That is if your tank is vented elsewhere other than the cap. Go for a ride and see if it leaks again. If so, it is the thread leaking.
If not, its the cap gasket.
If the tank vent is through the cap and piped up to a catch tank etc you will have to rig up a temporary vent through the blank.
What is this 'atmospheric pressure valve'?
👍

i'm attaching a pic of what i call the "atmospheric valve"

Enots Oil tank cap leaking
 
I believe i figured it out: after making all the oil connections of the tank air tight and closing the little vent holes inside the cap, i blew air through the yellow tube and it obviously leaked past the gasket.

I bolted the nut that holds the gasket in place further down, and by that put more pressure on the spring behind - that did the trick.

Now the spring is more pressured. I'll put some loctite on the nut and keep you updated once i'm up and running. Thanks for all your help.
 
With another the breather/vent, you can plug the hole(s) in the brass washers, sandwiching the rubber seals in the cap. Those holes are there to let air in when that cap is on a fuel tank, and is not needed on an oil tank with another appropriately sized breather. That hole in the cap is way too small for an oil tank breather anyway.

If you're getting oil out of that hole in the cap (and your other breather is functioning), you may be slightly overfilling your tank. Even with a good amount of frothing, it shouldn't come up to the cap.

All the above is assuming your other breather works. If it's plugged with goo (or the hose is crimped), your tank will be pressurizing from the return pump, and will make a mess forcing oil out wherever it can. An oil tank breather is the simplest part that can cause the biggest mess.

And, cleaning up oil spills with a cat sounds painful. I'd recommend a pile of rags.
 
With another the breather/vent, you can plug the hole(s) in the brass washers, sandwiching the rubber seals in the cap. Those holes are there to let air in when that cap is on a fuel tank, and is not needed on an oil tank with another appropriately sized breather. That hole in the cap is way too small for an oil tank breather anyway.

If you're getting oil out of that hole in the cap (and your other breather is functioning), you may be slightly overfilling your tank. Even with a good amount of frothing, it shouldn't come up to the cap.

All the above is assuming your other breather works. If it's plugged with goo (or the hose is crimped), your tank will be pressurizing from the return pump, and will make a mess forcing oil out wherever it can. An oil tank breather is the simplest part that can cause the biggest mess.

And, cleaning up oil spills with a cat sounds painful. I'd recommend a pile of rags.
Hey thanks a lot for this info. I’ll disassemble the washers again and try to close the air vent holes.

The oil tank breather seems to work well, there are a few signs of oil inside the yellow tube. It’s routed to drip as far away from rear brake/tyre as possible.

I’ll post a report over here when I did a test ride
 
Just a quick update, maybe it helps someone in the future: The solution was to adjust the nut inside the cap.
Now with this nut torqued further down, and by that pressuring the spring behind the cap seals more, the oil tank is tight and there are no more leaks.

Enots Oil tank cap leaking
 
Back
Top