Question about Fork Oil Level

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Jun 27, 2018 | 06:48 PM

pgilbert689

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Joined: Apr 2016

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From: Parker, CO

Question about Fork Oil Level

I have a 2012 1200C and I have pulled the forks off of the bike, taken off the cap and poured the oil out into a container to measure how much came out. I'm in the process of changing out my springs. Anyway, I drained out about 305ml of fork oil and this is with me turning it upside down and pumping the slider. Looking at my service manual, it says I need to have 366ml of fork oil. I'm not the original owner so I don't know if this has been changed before or if is the original fork oil. It doesn't appear that my seals are leaking either. Do I put in the 305ml back in or should I add back 366ml?

Jun 27, 2018 | 06:54 PM

BeardTillDeath

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Joined: Sep 2017

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From: Southwest Arizona

Position fork tube assembly upright. Compress the assembly fully.
Pour approximately 414 ml (14 fl oz) of HARLEY-DAVIDSON FORK OIL Type E into fork.
Pump the slider tube 8-10 times to expel air and compress the assembly fully.
Use the HARLEY-DAVIDSON PRO-LEVEL OIL GAUGE (Part Number:HD-59000-B) to draw off excess fork oil until it reaches the level specification.
Install spring and other components.
Install slider tube cap with O-ring. Screw tube cap all the way into slider tube. Finger-tighten only.

Your Fork Oil Level spec is 4.72 in / 120 mm

Last edited by BeardTillDeath; Jun 27, 2018 at 06:55 PM.

Jun 27, 2018 | 06:54 PM

Yamaharley

Outstanding HDF Member

Joined: Oct 2016

Posts: 2,530

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From: Wayne County, PA

Are the springs stock? If so then i would put whatever the service manual says. Over time fork tubes loose oil. I had mabye 3oz in each tube when i changed mine after buying the bike. It was never changed by the look of it. This is why changing the fork oil every few years is very important.

Jun 28, 2018 | 02:58 AM

kap1

Road Captain

Joined: May 2017

Posts: 559

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From: VA-Nelson Cty

I usually pour in a couple of ounces and pump the forks a few times and dump again to flush them out well before filling and doing all the measuring stuff. Made my own gizmo to suck out oil to correct level. While an ml here or there won't amount to anything I do use a level to keep the tubes perpendicular/sq/ when measuring.

Jun 28, 2018 | 06:17 AM

Campy Roadie

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Joined: Aug 2011

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From: SW Ohio

Forget the fluid oz measurement and use the measurement in mm from the top. It's much more precise.

Jun 28, 2018 | 10:07 AM

Rengnath

Tourer

Joined: Sep 2017

Posts: 300

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From: Milwaukee

The information above is correct. When I replaced my sliders, I used the 366ml as a starting point, but then the manual goes through the process of measuring the level of the oil, with the tube compressed, and the spring not installed.

I used this tool and it worked perfect: https://www.denniskirk.com/motion-pr...prd/284159.sku
You set the gauge and lock the guide on the rod, put it in the tube, and then use the syringe to draw out any extra fluid.

Jun 28, 2018 | 08:27 PM

65Tiger

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Joined: Jun 2016

Posts: 396

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From: Maple Ridge BC & Chiangmai

Quote:

Originally Posted by Nomadmax

Forget the fluid oz measurement and use the measurement in mm from the top. It's much more precise.

Exactly and use a proboscis type sucking tool like the factory issue to set the level - I make my own using a big syringe
Note that the oil is measured without the spring installed!

Remember that all oils are not created equal and one manufacturers 5W is anothers 10W
Take a look at this - if your eyes glaze over go straight to the viscosity chart and all will become clear
http://www.peterverdone.com/wiki/ind...spension_Fluid

Remember that air is part of the spring, and by varying the air gap you can change the characteristics. Start with the factory level, and then vary the gap to achieve the desired result.
Remember to set the spring rider static sag - I use 25% of total travel for street use