My Riff Raff boot is doing the same thing after just a couple of years...sweating oil.

 

Re-route the CCV into a filter or atmosphere.

Get it outta your turbo

 

There is a reason silicone hose is not used for hydrocarbons such as oil or crankcase hose, it’s not defective just the nature of the material when used with hot oil vapor passing through it. When I rebuilt my engine I started over with a virgin intercooler, turbo and cleaned out the intake. I had my pipes powdercoated and cleaned my RiffRaff boots with dawn and hot water to get them 100% clean of oil then hairsprayed all connections. Zero oil in my intake. I had a 1” hose running to the rear bumper down the frame rail but it started causing crankcase pressure to build enough to cause oil leaks. I went with a Mann Hummel ProVent 400 recently and it scrubs my crankcase vapors before they are ingested by the turbo intake. I put a Fumoto valve on the bottom drain of the filter and drain a little bit of nasty drip about once a month.
The age old argument is turbos need the oil to stay lubricated but this is a myth. Just to prove how crank case pressure causes excessive blow by Charlie Fish recently released a video illustrating exhaust haze or blow by from a truck with a CCV reroute gone wrong that caused the crank case to build back pressure and the vapors escape past the piston rings. He removes the oup fill cap and takes the truck for a hard accelerating romp to burn off any remaining vapor in the system and when he gets back there is no visible blow by.

 

Is it possible that in your case the long hose to the rear bumper has created a kind of "back pressure"? In my case, the hose ends at the transfer case. I have had no problems so far.
The inner diameter should be sufficient in your case with 1".

 

Yes because I had the short hose that stopped at the transfer case with no oil leaks. I added the long hose because I got tired of the smell of the vapors and that’s when the oil leaks started. Now with my CCV filter and routed back to the intake so the vapors are drawn through the turbo my oil leaks are gone. With the long hose I had oil leaking from the turbo drain, oil dipstick to block, bed pan, oil pan and glow plug harnesses on both sides.

 

Which CCV filter did you use?

 

Mann Hummel ProVent 400 - post #18

 

https://www.dieselfiltersonline.com/...f-highway.html

Another solution for those that want to "free-vent" such as Mac's original or Hartwig's situation is to add 2", 2 1/2", or 3" PVC electrical conduit under the truck to go farther back. That should relieve back-pressure.

 

thank you for the link.