It appears that the standby solution for wet sumping (or oil draining to crankcase) of cleaning and / or repairing the "check valve" does not apply to the Twin Cam engine.

The Twin Cam does not have a check valve. Rather I should say I can not find one on 03 and newer Twin Cam 88 and 88B engines.

There is an oil pressure relief valve that dumps oil from the pump output back to the pump input but unless its o-ring is leaking there is no way for that oil to enter and collect in the crankcase.

The probable cause of excessive oil drainage in your Softail is a worn "wavy washer" or damaged o-ring in the oil pump body. Due to the design of the oil pump and oil system there is most likely no practical way to prevent oil drainage completely.

Worn or damaged scavenge lobes on the oil pump will also lead to wet sumping, but in the case of a worn or damaged pump the oil would build up the longer you ran the engine. So if you check the oil level at the end of a ride and it is low or totally gone you could have a damaged scavenge section of the pump.

If your oil level starts out low but is normal after a ride then you may need to have the oil pump or oil relief o-ring serviced.

How much drainage is excessive? If it drains out of the oil bag in 48 hours or less my choice would be to get it serviced.

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Would experienced TC mechs please add to this or let me know if my information is totally off base.

Thanks

 

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