The Hoesli Diesel Valve Cover Kits are sweet yet simple redesign of the Cummins On Highway/Industrial/Marine valve covers. We remachine the valve covers to accept two (2) 1/2" lines that run to a catch can (mounted where ever the customer desires). 

The catch can has a 3/8" drain line that runs back into the 3/8" drain line that runs from the back of the valve cover. This 3/8" line attaches to the factory drain check valve. It is important to drain into this check valve as it keep crankcase pressure from coming back into the catch can. Oil accumulated in the catch can drains back into the block. The eliminates having to remove the catch can and drain it. Also, always mount the catch can higher than the block drain location. It must always be going downhill. 

It is also important to keep the catch can filter clean. It will become filled with oil from the vapor exiting through it. If this filter is not attended to, it will become saturated with oil and run all over the catch can. It can make a mess......