Remove Crankcase Pressure with Feuling Vented Oil Dipsticks

remove crankcase pressure with feuling vented oil dipsticks

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The Feuling Billet Vented Dipsticks vent/breathe excessive crank case pressure from the oil tank through a PCV style breather, consisting of an oil separator system, perforated disc, replaceable filter element and umbrella flapper valve. Feuling vented dipsticks screw into the factory oil fill spout as a stock replacement part. These breathing dipsticks remove unwanted build-up of blow by pressure in the oil tank.

Now, what is “Blow by” you ask? It is pressure that is forced past the rings and cylinders, pushed into the crankcase and then forced into the oil tank. Feuling dipsticks help remove this unwanted pressure through a Crankcase Ventilation System (CVS). Test results show a decrease in engine oil sump levels, more freely/smoother revving engine, increased MPG and decreased blow-by.

NOTE: All internal combustion engines have a certain amount of blow by. Larger cubic inch engines as well as engines with worn and or loose ring clearances will have increased blow by. Engines pushed to their limits will also produce excessive build up of power robbing blow by.

The Feuling Vented Dipsticks are available in polished or fade resistant black finish.

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Feuling’s Vented Dipsticks include two venting style options to choose for installation.


1/8 NPT breather vent fitting with internal porous filter element. This option gives a clean look however it can produce an oil misting/residue out of the element on engines with excessive leakdown/blow by.

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Feuling’s Vented Oil Dipstick Option 1 features a 1/8 NPT breather vent fitting with internal porous filter element.


Quick disconnect coupler fitting with rubber hose and filter element. This option will run any excessive oil misting/residue through the line and into the filter element. However this option does requires disconnecting the fitting in order to check the oil. This is Feulings preferred option as it breaths more than option 1. For option 2, Feuling recommends routing the line up the frame rail, up under the seat/abs area then back down along the right side frame rail and the filter element can fit cleanly between the engine/trans matting area on the inside of the lower right frame rail.

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Feuling’s Option 2 features a quick-disconnect coupler fitting with rubber hose and filter element.

Checking Oil Level
There are two ways to read the oil level with this dipstick, with the bike on the jiffy stand (FHS) or the bike upright and level (FHU).

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If reading the dipstick with the bike on the jiffy stand you will take your reading from the dimples labeled FHS (Full Hot Stand).


When reading the dipstick with the bike upright and level you will take the reading from the dimples labeled FHU (Full Hot Upright).

It is important to get the correct hot oil level in your bike. Feuling recommends running the oil level 90%-99% full when hot.

TECH TIP: Feuling highly recommends staying off the rev limiter and running conventional oil in the M8 engines to help maintain ring seal and minimize blow by.

Note: The oil pick up port is on the right side of the engine. Letting the bike idle or warm up on the kickstand will naturally fill the engine case and skew the oil level in the tank.

Feuling recommends the following steps to achieve proper oil level:
1. Check cold oil level.
2. Ride the bike until operating temperature is reached.
3. Shut the bike off while still in the upright position. (This insures an accurate reading)
4. Once the bike is on the kickstand check oil level.
5. Add or remove oil as needed

FITMENT: Feuling offers its Vented Dipstick Kits for multiple Harley-Davidson Models. Click HERE to find the correct fitment for your motorcycle.


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