Dry sump oil tank drain plug leaking

[KnifeySpoony]

My new 420R wants to leak from the drain plug on the dry sump tank. Tank is aluminum, and with the copper washer, I figured would need very little torque. Initially only had about 5ftlbs on it. Leaked. Increased to 10. Leaking. Increased to 15. Leaking. Increased to 20. STILL LEAKING!! How tight is safe? I'm thinking about just pumping out all the oil, taking out the drain plug then putting it back in with some thread sealant or just JB weld it in LOL. My plan is to pump the oil out of the tank rather than drain it, which seems to be the favored technique. 

 

Anyone with any tips?

[sf4018]

Make sure the port and screw is clean, use a fresh copper washer each time you take the screw off.

[KnifeySpoony]

Hmmm this is a new build and the bolt/washer were prefitted into the tank, but were loose. I never took them out to inspect/clean. I just torqued it up then filled it up. I suppose it's possible some debris is preventing sealing.

[Dave W]

I would check for debris in the threads. If that is not the issue, then I would try Permatex thread sealant # 80632.  This is the type of sealant used on engine bolts that go into the water jack or crank case. Does not harden, so there is not a removal problem.   Dave W

[KnifeySpoony]

After the bump up in torque to 20ftlbs yesterday afternoon, this AM the leak is worse. Small pool of oil under the car. I'm going to drain it today then do thread sealant -  I have some Permatex 59214. Hopefully it works.

[KnifeySpoony]

Mystery solved. Clearly the wrong sized copper washer was installed from the factory. 

[KnifeySpoony]

I got a new washer. Better fit but still used some loctite 592. Probably will never remove it again.

[empti]

I ran in to the same problem. The left is the OE bolt & washer, the right (M10x1.25) bolt and washer were from Amazon. Let's hope it resolves the issue. 

 

[panamericano]

Was the original a one use, crushable washer?

[CBuff]

Wow. Learned something new. I didn’t even know there was a drain plug on the oil tank (new 420r).  I have just been vacuuming the oil out for changes.  Maybe I will locate it and just make sure it’s not leaking (haven’t noticed anything).  
 

I did chase down oil coming from the breather bottle at track days. It was blowing into breather and then right out the over flow tube and down the right side of the car.  Pulled the tubes up (they were both sitting at the bottom of the breather bottle thereby negating its existence. Since I pulled them up I haven’t had that issue. 

[KnifeySpoony]

Fwiw my solution solved the leak and i never touched it again. 

 

Re:oil overflow, yeah i had to cut the tube inside the bottle much shorter as it was near the bottom of the tank. 

[empti]

5 hours ago, panamericano said:

Was the original a one use, crushable washer?

Yes, but it's not the right size. 

[empti]

4 hours ago, CBuff said:

Wow. Learned something new. I didn’t even know there was a drain plug on the oil tank (new 420r).  I have just been vacuuming the oil out for changes.  Maybe I will locate it and just make sure it’s not leaking (haven’t noticed anything).  
 

I did chase down oil coming from the breather bottle at track days. It was blowing into breather and then right out the over flow tube and down the right side of the car.  Pulled the tubes up (they were both sitting at the bottom of the breather bottle thereby negating its existence. Since I pulled them up I haven’t had that issue. 

The leak was very noticeable, I had a stream of oil on my garage floor after parking it overnight. I think the vibration caused the washer to move a bit and that explained why it didn't leak that much during my assembly process.