|Posted on Saturday, February 06, 2016 - 08:31 pm: ||
Has anyone accurately measured the fork oil capacity?
I'm in the process of changing the oil in my forks. I was draining the fork tubes into a clean container for the purpose of measuring it but knocked it over. Ugh. It's tough to measure the volume of oil that's all over the floor and being lazy, I don't want to disassemble the forks just to check the oil level when refilling it. Besides, I don't have one of those fancy factory spring compressor tools.
After draining what's in there, how much do I need to pour back in?
|Posted on Saturday, February 06, 2016 - 08:55 pm: ||
The capacity isn't in oz. but in height. The fork oil level is 94mm from the top.
The recommended fork oil is HARLEY-DAVIDSON FORK
OIL TYPE E (Part No. HD-99884-80).
• The fork spring should not be installed for this part of the
2. With the fork fully collapsed, fill the fork with oil until it
reaches the threads on the outer tube.
3. See Figure 2-90. Thread damper rod retrieval tool found
in the Race Tech Inc. FORK BLEED TOOL SET (Part
No. TBFT 02S) onto end of damper rod assembly.
While pumping the outer tube up and down be sure not to
exceed the travel of the fork assembly.
4. Pump the damper rod assembly approximately 12 to 15
times or until resistance is felt.
5. Collapse the fork again and once bubbling has stopped,
pump the damping rod up and down its full stroke until
consistent resistance is felt for the entire stroke.
6. See Figure 2-91. With fork completely collapsed, adjust
fork oil level with FRONT FORK OIL LEVEL GAUGE (Part
No. B-59000A) to the specified level below the top of the
fork tube. Refer to Table 2-19.
|Posted on Sunday, February 07, 2016 - 09:38 am: ||
Thank you Lance, I am aware of the factory procedure for checking fork oil height which requires disassembly of the fork spring which I'm attempting to avoid.
I am looking for the exact volume of oil in the forks.
|Posted on Sunday, February 07, 2016 - 09:47 am: ||
The reason they use height vs volume is you have wet vs dry forks. You add to much oil and you can get hydro lock and to little and you'll get air in the oil. Most of the forks out there now use height, it's the best way.
|Posted on Monday, February 08, 2016 - 02:11 am: ||
It takes a bit over a pint per leg for complete rebuild - maybe a half oz to oz more.. that's as exact as I can recall - I use the oil level gauge, so some gets sucked up and returned to the bottle, but it still takes over two pints to do the job. The info may be in the service manual specification section.
(Message edited by Stirz007 on February 08, 2016)
|Posted on Monday, February 08, 2016 - 09:57 am: ||
Thanks. I overcame my laziness and disassembled the forks yesterday - using the ratchet strap and S-hook method. It worked very well for an improvised tool.
I'm glad I did. I had previously removed the fork cap from the fork tube and left the cap attached to the damper rod. I inverted and drained the fork tube overnight. I thought it was pretty much empty. When I eventually removed the fork cap from the damper rod and pulled out the long rebound damper needle, another couple ounces of fluid came out. That would have guaranteed that any estimated volume would have been excessive and that I really hadn't adequately changed the fluid.
There really is no way to achieve the correct volume of fork fluid without removing the spring etc. and measuring the level as per the service manual.
96mm and all is well.