Fork oil level question
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Road Master
Joined: Jul 2010
Posts: 963
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From: Bellefonte PA
Fork oil level question
Can someone explain this to me please? In my 04 service manual, when referring to Road King fork oil there is some confusion (for me anyway). In the section on changing fork oil it basically says drain the fluid, refill with 11.1 ounces, button it back up and get on with your life.
In the section detailing disassembly/reassembly, it states the same 11.1 ounces but then specifies using the oil level gauge to set the fluid height to 5.24 inches from the top of the tube.
Why is the fluid height critical after assembly, but not after a simple fluid change?
In the section detailing disassembly/reassembly, it states the same 11.1 ounces but then specifies using the oil level gauge to set the fluid height to 5.24 inches from the top of the tube.
Why is the fluid height critical after assembly, but not after a simple fluid change?
Outstanding HDF Member
Joined: Jul 2010
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It's the same, just extra wording to confuse you. Pour it in VERY slowly or it will spill out the top and you won't know how much you spilled so you will have to do it over again.
You don't need anything except to measure the correct amount and a funnel with a tube on it.
You don't need anything except to measure the correct amount and a funnel with a tube on it.
Outstanding HDF Member
Joined: Jan 2010
Posts: 2,916
Likes: 31
From: earth
Can someone explain this to me please? In my 04 service manual, when referring to Road King fork oil there is some confusion (for me anyway). In the section on changing fork oil it basically says drain the fluid, refill with 11.1 ounces, button it back up and get on with your life.
In the section detailing disassembly/reassembly, it states the same 11.1 ounces but then specifies using the oil level gauge to set the fluid height to 5.24 inches from the top of the tube.
Why is the fluid height critical after assembly, but not after a simple fluid change?
In the section detailing disassembly/reassembly, it states the same 11.1 ounces but then specifies using the oil level gauge to set the fluid height to 5.24 inches from the top of the tube.
Why is the fluid height critical after assembly, but not after a simple fluid change?
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
Likes: 402
From: Phoenix '53, '88, '09 Big Twins
I would say- pretty critical.
the amount of compression, damping and rebound needs to be the same on both fork legs.
Mike
Supporter
Joined: Aug 2008
Posts: 5,189
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From: N.E. Wisconsin
Fluid height is most important because of oil thats still in the cylinders, put in the oil slowly. Work the forks a little till you've got about 10.5 oz in, then measure, add a little if necessary, measure...etc.
Outstanding HDF Member
Joined: Jul 2010
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Some people have a tendency to over complicate things, if you are one of them go for it. But it is not necessary. Just drain the old stuff and very slowly pour in the correct amount of new stuff. You could pour in ˝ or ž then wait 10 minutes before pouring in the rest. It doesn’t need to be any more complicated than that.
There is always some oil left in the cylinders but you will leave oil in the measuring cup, funnel and tube as well, so just use the correct amount and it all evens out. Don’t worry about it being off .1 of an ounce one way or the other, the bike will never know the difference and neither will you. If anyone says they can tell the difference in .1 oz they are kidding themselves.
Those drain plugs are tight, make sure you have something to break them loose without stripping the heads. Also the nuts on top have limited space around them, not just any tool will fit in there. An open end or box end wrench works well, if you use a socket it will need to be very low profile.
There is always some oil left in the cylinders but you will leave oil in the measuring cup, funnel and tube as well, so just use the correct amount and it all evens out. Don’t worry about it being off .1 of an ounce one way or the other, the bike will never know the difference and neither will you. If anyone says they can tell the difference in .1 oz they are kidding themselves.
Those drain plugs are tight, make sure you have something to break them loose without stripping the heads. Also the nuts on top have limited space around them, not just any tool will fit in there. An open end or box end wrench works well, if you use a socket it will need to be very low profile.
Last edited by jjnoble; Sep 26, 2012 at 12:08 PM.
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Road Captain
Joined: Dec 2009
Posts: 540
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From: Nooga, TN
[QUOTE=jjnoble;10376380]Some people have a tendency to over complicate things, if you are one of them go for it. But it is not necessary. Just drain the old stuff and very slowly pour in the correct amount of new stuff. You could pour in ˝ or ž then wait 10 minutes before pouring in the rest. It doesnt need to be any more complicated than that.
There is always some oil left in the cylinders but you will leave oil in the measuring cup, funnel and tube as well, so just use the correct amount and it all evens out. Dont worry about it being off .1 of an ounce one way or the other, the bike will never know the difference and neither will you. If anyone says they can tell the difference in .1 oz they are kidding themselves.
Those drain plugs are tight, make sure you have something to break them loose without stripping the heads. Also the nuts on top have limited space around them, not just any tool will fit in there. An open end or box end wrench works well, if you use a socket it will need to be very low profile.[/
It is NOt that critical on a touring bike. Only the overly **** ones care about + or - .25" in height. Racing bikes and/ or other types of forks, maybe, but not a Tourer.
There is always some oil left in the cylinders but you will leave oil in the measuring cup, funnel and tube as well, so just use the correct amount and it all evens out. Dont worry about it being off .1 of an ounce one way or the other, the bike will never know the difference and neither will you. If anyone says they can tell the difference in .1 oz they are kidding themselves.
Those drain plugs are tight, make sure you have something to break them loose without stripping the heads. Also the nuts on top have limited space around them, not just any tool will fit in there. An open end or box end wrench works well, if you use a socket it will need to be very low profile.[/
It is NOt that critical on a touring bike. Only the overly **** ones care about + or - .25" in height. Racing bikes and/ or other types of forks, maybe, but not a Tourer.
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Outstanding HDF Member
Joined: Jan 2010
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From: earth
The purpose of a bike's use does not negate the value of a good suspension. A touring bike is meant for long distance riding and casual cruising, I can't think of an application better suited for a well tuned and comfortable suspension. Those on the other end of the spectrum who don't care much about measurin' and torquin, and other nonessential maintenance what nots, are probably correct that they will never know the difference, because they will never achieve peak performance with their shade tree techniques and practices, to know the difference. Skully, since you did your homework on front suspension options and decided on a product that delivers exceptional performance, well beyond stock, I would assume that you're not looking fer a "good nuff" answer. I only recommend the manual quoted fluid height value because its easy to reference and I know it works. I will agree that a little more or less probably won't make a difference, but I also agree that both tubes should be equal, and if you take the time and effort to make them equal you might as well just make it right too, while your at it. You're not doing a generic jiffylube fluid swap on your forks, you are upgrading valving, springs, fluid, and "tuning" your front suspension. "tuning" is not routine maintenance, its a custom adjustment to achieve a specific set of desireable charcteristics for a given set of conditions, and it requires "****" and "overly complicated" procedures and practices to accomplish it.
