Front Fork Fluid level FLHX
Thread Starter
|
Intermediate
Joined: May 2010
Posts: 39
Likes: 2
From: Troy, Ohio
Front Fork Fluid level FLHX
Last year I changed out the original fork sliders to chrome and installed new seals. I did not have the fork oil level gauge so I measured 10.8oz of fluid (what the manual calls for) with a digital scale so I made sure I had the right amount of fluid. So this year I wanted to change the fluid again this year, I know you don't need to but I had 14,000 miles last year but I like to change all the fluids. I purchased a level gauge this year and I set the gauge at 142mm and I pulled out about 2 to 3 ounces of fluid using the gauge and I weighed the fluid that came out and it was 10.4oz so I set the level gauge to the other fork that I did not drain and that came to 92mm on the scale. 10.8oz of fluid = 92mm on the fork level gauge and not 142mm.
Long story short do I put in 10.8oz or 142mm on the level gauge? One of them is not right and I wonder if it is because the FLHX has a lower suspension than the FLH. I ran all last year with 10.8oz of fluid in the forks and they seemed fine.
Long story short do I put in 10.8oz or 142mm on the level gauge? One of them is not right and I wonder if it is because the FLHX has a lower suspension than the FLH. I ran all last year with 10.8oz of fluid in the forks and they seemed fine.
Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
They are both correct. The fl/oz measurement is a start point with just enough extra to ensure the "sucker" will contact the fluid, the linear measurement from the top of the fluid to the top of the collapsed tube is the final adjustment.
Thread Starter
|
Intermediate
Joined: May 2010
Posts: 39
Likes: 2
From: Troy, Ohio
At 10.8 ounces poured in the tube the sucker pulled out 2 to 3 ounces of fluid. Which would make around 7.8 to 8.8 ounces in the tube. I don't think you should have that low of fluid in the forks.
Ultimate HDF Member
Joined: Feb 2006
Posts: 5,190
Likes: 5
From: Eastern Washington
You sure about that? What is the density of the oil you are using?
Trending Topics
Cruiser
Joined: Sep 2006
Posts: 171
Likes: 0
From: Frederick, MD
Not true....measure liquids in a measuring cup and dry on a scale
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider
Verdad Gallardo
The Best and Worst Harley-Davidson Moves of 2025
Verdad Gallardo
Thread Starter
|
Intermediate
Joined: May 2010
Posts: 39
Likes: 2
From: Troy, Ohio
My bad. I did the calculations. The specific gravity of 10W and 20W oil is between .88 to .94 and after the calculations 10.8 fluid ounces of oil = 11.38 ounces in weight. Which means that I have less oil in the forks but a mechanic told me that you can off by as much as 1 to 2 ounces and you will be fine.
Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
Ditch the digital scale and the specific gravity conversion formula, and just get a cheap measuring cup with a fl/oz scale. Bottom line is the linear measurement from the top of the fluid to the top of the collapsed tube is whats critical, doesn't matter how much fluid is left after the linear measurment, or what units of measurement you use to account for what's left over.