I just got my new coupler from Intense, but until I have the time to replace it, I have taken the belt off and I'm driving "naturally aspired" (I miss the boost already). After two days of driving without the belt I noticed that the bolt on outside of the pulley is wet and dripping SC oil. I guess the leak is now noticeable since the pulley is not spinning off the leaking oil.

When I pull the nose to replace the coupler, what do I need to do to fix this leak?

I did a search for other posts, but can't find one that gives me a definite answer. Is it the breather cap, or is it the shaft seal ?

Ok, first off we need to ask for this to be moved to the Force Induction area to get you better exposure to those that can help the best.

To change a coupler:
New coupler
2 bottles of GM SC oil
1 small tube of GM Red Gasket Maker

Disconnect battery
Remove alternator
Drain oil from SC with sprayer pump from old spray bottle
remove 8 or so bolts holding nose drive on SC (dont' forget the one that is postioned straight down into lower intake manifold.
Slide nose drive off
Remove coupler
Clean all surfaces
Put new coupler in
Put red gasket maker on nosedrive side.
Put nosedrive back on
Bolt and torque.
Put alternator back on,
Connect battery
Add 2 bottles of SC oil
Cap and call it done.

Thanks for the step-by-step. I was pretty sure how to replace the coupler and you confirmed that for me.

My question was, how do I stop the leak at the pulley.

Is the leak behind the pulley or in front. Sounded like it was coming out the breather hole. Which.. should be able to breath.

If it'* coming out the breather hole, it'* because your boost pressure is getting past the rotor seals into the oil cavity. But if it'* not running, that doesn't make sense. How much is coming out? Is it possible it was oil from before the belt removal?

What'* your oil level?

The leak is coming from the bolt side of the pulley. It is leaking around the bolt. The back side of the pulley (nose side) is dry. It appears to be steadily seaping out around the bolt. I dried it off this morning, but it is soaked again and slightly dripping.

I have not checked the oil level yet, since I only noticed the leak a few days ago when I took the belt off.

Well, the earlier M62 superchargers don't have that breather, so I'm at a loss to help you with it. Are the M90 breathers replaceable? Don't most of you guys that 'hub' just plug them anyway?

Does INTENSE sell the plug?

Where is that plug located ?

I have not had the pulley off, so I can't picture where it would be.

If the pulley is off, would there be enough pressure to cause a leak at the breather?

Intense sells the snout seal, but not a breather cap/seal, at least that I could find.

On the M90, the breather cap is simply a solid screw in type plug. Which is why I never understood calling it a breather.

Can you get a pic of this leak, I'm interested to see the amount of actual leakage.

I don't have my camera with me, so I will take a picture tonight. I will completely dry it off before driving home tonight and then take the picture when I get home (after a 30 mile drive).

If it is the breather cap that is leaking, wouldn't there be oil on the nose side of the pulley, rather than the bolt side?