So this winter I had the upper and lower rockers off. Had cam cover and tappet blocks off, now I've got an oil leak from bottom of the cylinders off both sides of the engine case, mostly the left side, cleaned it several times. Seems to be the front cylinder base gasket. Ive heard that head gasket leaks can drain down the bolts and look like a base gasket. There is no oil at the top of the engine at all. I'm an auto tech so I just dont get how it started leaking when I had the rockers off. Nor can I understand how to diagnose the leak.
Its on my 2009 road glide with 106 S&S big bore kit installed for over 4 years now,
Any help you guys can give me would be awesome.

 

Clean everything up and look closer for the source of he leak, particularly the tappet block gaskets. After four years, it is unlikely that the cylinder base o-rings started leaking. I suspect with closer inspection you will find the leak elsewhere.

 

If you lay long rubber patches out of parking lots or before bike is up to operating temp the base oring or base gasket can be breached, just taking a stab at a cause 4 yrs post build. Even knowing better I’ve made this mistake

 

I dont see how the lifter blocks could leak up and over the engine case and leak down the primary before leaking down the right side

 

Just saying that the source of oil leaks can be tricky to find and you did say that the leak presented on both sides.The rocker box gasket surface is in the same plane as the cylinder base o-ring and oil leaking from the rear of the tappet block could easily move around to the cylinder base and present as a leak at the cylinder base. I have seen that on my own bike. I doubt that, out of the blue, after for years that base o-rings started leaking and the leak is more likely associated with the upper/lower rocker box and tappet block R/R and that is the first place to start tracking the source of the leak. Unless, you have done what NTDave describes in his post that could have caused a leak. Usually base o-ring leaks do no present as "leaks" but present as seepage. However, if you believe otherwise, you should have re-torqued the head bolts when you had the lower rocker boxes off. You can still do that and if the leak stops, you go lucky. Once a base o-ring starts to leak, replacing it is usually the fix. Just saying, check the last thing you did first to try and track down the leak; it's not that hard to do and a lot easier than pulling the cylinders to replace the base o-ring.

 

My guess is that cylinder base O rings got hard and are leaking. The problem stems from how much heat the motor sees and whether or not you used viton cylinder base O rings or not on the build.. IIRC some Cometic kits had Buna-N, no clue on James / Drag. Cyco kits were viton. IIRC early HDs were buna but the later ones I bought from HD were Viton. Pretty much all the O rings in the new M8s are viton.

 

How do you retorque the head bolts without loosening them my manual gives me degrees as the last torque sequence? Also what do you mean the rocker box gaskets are on the same plane? If the lower housing gaskets were leaking it would have to run down the fins of the jugs right?
I do appreciate the help cleaned it several times I think the front tappet block is leaking. But I still get oil drips from between the jugs. O well winter project. Was hoping to not have one but I well.

 

"Rocker box gasket in the same plane" was a typo; apologies, my bad; should have been "tappet cover gaskets".

First thing I would do is stop the tappet block leak; get it out of the way.

You did say that the S&S 106" BB kit had been installed 4 years back, right. I would bet that a Cometic MLS head gasket was used when the kit was installed and Cometic instructions for their gaskets to not follow the manual specified "degree" method. Cometic instructs to torque in four steps, the last being to 42 ft.lbs. So, set the torque wrench (needs to be a good one that is accurate) and check TQ on each head bolt. I would go so far as to then set to 45 ft.lbs and hit them again.

Like Max suggests, after stopping the tappet cover leak, get the top end really clean and dry, take a short ride, come back and look for the leak. If base o-rings are leaking, it should present pretty quick. Might even consider adding a dye in the crank case that will show under a black light.

Your leak is most likely not related to your R/R of the rocker boxes and/or the cam plate; coincidence.