87 Softail Custom, and when it sits, oil gets into the case, and has to be pumped out while cranking the starter. When I rode it everyday in the summer, there would be only the smallest amount of oil or none at all being spit out the vent tube, but after sitting for a couple of months, the oil has built up in the case. I have read multiple posts stating various oilpump types for this engine. Can any tell me with certainty which oil pump is in this engine? and what the course of action is to fix the leak? Thanks.


update- while continuing my search I dug up an old thread all about this topic, and with varying ideas, but it should contain everything that would come up here...
https://www.hdforums.com/forum/evo-c...-question.html

 

It's the one with the check ball leaking..

 

Your problem is most likely to be the non-return valve in the top of your cam chest. I don't believe it has anything to do with the oil pump itself. Sumping is a common problem on older Harleys, especially shovels and Evos. Do you have a factory service manual? There is an excellent description of the lubricating system in it, well worth reading.

 

FWIW It's not a non return valve.. It's a popoff valve that is in the oil pump.. I called it check but that is not correct also.. While it does not allow reverse flow (Check or non return) it is really a valve that allows oil to flow at really low pressure. It's in the oil pump and has pretty much been in the pump since 1933 until the introduction of the twincam. The plug in case has the tappet filter screen.

The common issue is the valve fails to seat or the spring is weaker than it should be, oil from the above mounted tank can leak into the motor. The common fix is to drop the a ball into the hole and tap lightly on it with a punch, fish it out and replace with new ball and spring.. Old pumps that were cast iron, we used to lap the ball into the seat.

Another place the oil can leak into motor is an oil seal between the feed and scavenge side of the pump. Partially shown in the pick (#19).. Need to remove the pump to get to it..

You can see parts lists for later models on..

http://partsfinder.onlinemicrofiche.....asp?make=hdmc

 

It is indeed referred to as a check valve as per the FSM as an assembly but listed individually as check valve ball and check valve spring...

 

Yeak in my case it's really too much information.. Technically it's not on any bike here the tank is mounted above the pump.. Later baggers where the pump is slightly above the oil tank level, it's a check valve as it keeps oil from flowing back into the tank. HD has been calling them check valves since the 30s but they really aren't used in that fashion (except for the bikes with the oil tank mounted lower)..

Check valves block reverse flow but as HD used them they are mainly a low pressure relief valve. It keeps the oil from flowing forward until the pressure is above a couple PSI..

 

The check ball prevents oil from flowing from the tank into the oil pump when the engine is not running, on a bike with an oil tank that is higher than the pump (pre Twin Cam). If the oil gets past this check ball when the engine is not running, it will end up accumulating in the crankcase.

The check ball and seat are part of the oil pump assembly.

 

Here I posted this a few years back, complete how to to help with the common check ball issue. Only thing I'll add is get new spring & ball to do this the springs do lose tension as they age.

https://www.hdforums.com/forum/gener...ll-repair.html

 

Yes, not an uncommon problem on a gravity-feed, oil-bag bike.
Lapping MAY help.
Mixed results over the years with this.
We even have the cutting tool that S&S uses to establish that seat area in their pumps.
It seems to work better.
Scott