S&S Cycle HVHP Oil Pump Kits for Big Twin - Manual (Page 9)

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All S&S® 1992-later style cases and most 1992-earlier stock crankcases have provision in rear of cam-side crankcase for two pipe-thread fittings. Fitting
above the oil pump is for vent line from oil tank. The bottom hole is used as crankcase breather on 1992-earlier models and on S&S engines set up
for crankcase breathing or combination crankcase-cylinder head breathing. Engine must have 1992-earlier style cam cover and gasket for crankcase
breathing; otherwise, large oil losses will occur out the bottom hole. The vent fitting will be used in all applications. The bottom hole will be used in most
crankcase breather situations. Any crankcase breather hole not used must be blocked.
J. Removing pump for service.
1- Disconnect oil lines.
2- Loosen pushrods.
3- Remove gear cover.
4- Remove cam.
5- Remove pinion shaft hardware.
6- Remove oil pump drive shaft gear retaining ring.
7- Remove oil pump cover.
8- Push pump drive shaft towards transmission to gain access to retaining ring and key, remove retaining ring/key.
9- Remove feed gears.
10- Remove remaining pump bolts and remove pump assembly from drive shaft.
APPENDIX: Oil Line Routing
Most big twin oiling systems utilize three oil circuits: supply, return and vent.
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Supply circuit delivers oil from tank to supply fitting of oil pump cover. See Picture 3. In motorcycles with oil tank located above
transmission, supply fitting in oil tank is almost always located on bottom of tank at center or rear. In Harley-Davidson® Dyna®, Road
King® and other models with oil tank below transmission, supply line exits oil tank on bottom of primary drive side, then crosses to cam
side and connects with supply fitting on oil pump cover.
To distinquish oil tank's supply from return fittings, remove oil lines and pour small amount of oil into tank. With motorcycle in upright
position, oil will flow out supply line fitting.
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Return circuit delivers oil from return fitting in oil pump cover, see Picture 3, through oil filter and cooler (if applicable), to return fitting
in oil tank.
In horseshoe-type oil tanks used on Softail® models, OEM rigid frames and many custom applications, two fittings nearest front of oil
tank are identical. Fittings may enter through upper area of tank or connect to fittings near bottom that are attached to standpipes
inside tank. THese fittings are for oil return and vent lines and in most cases may be used interchangeablly. Main exception is with oil
tanks with in tank oil filter.
In Dyna, Road King, and other models with oil tank located below transmission, return fitting is on top of oil tank nearest center of
motorcycle. Vent fitting is beside return fitting.
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Vent circuit equalizes pressure between oil tank and crankcase. See preceding paragraph for location of vent fitting in oil tank. Vent line
runs from vent fitting on oil tank to fitting in crankcase located above the oil pump.