'07 Fork Oil Change

D

Dr. Greenthumb is famous

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The procedure in the '07 service manual for a fork-oil change specifies removing the fork, fork-tube plug, and spring (among other things)--then inverting the fork for the fluid to drain. Looking at the parts manual I can't figure out why you couldn't simply use the drain plug, then remove the top plug and add the new oil from the top.

For those of you who've changed the fork oil in your '06 or later FLH, here are some questions:

(1) Is the fork-tube plug (45838-77) hollow so that oil can pass through it when added from the top hole?

(2) Will all fork oil drain from the drain plug, assuming the forks are pumped repeatedly?

If the answers to both are "yes," I can't see why a fork-oil change wouldn't be only a matter of draining, moving the top plug, then adding oil at the top.

Changing the fork oil in my old '96 RK was a 15-min. proposition by just draining and applying a vacuum at the schrader valve to suck the new oil in through the drain plug. If all the oil could be drained from that fork, why not the newer models? I'm not talking about cartidge type forks, but the forks HD has been making for the past few years.
 
Should be able to drain and refill using "wet" capacity. Replaced my lower sliders with chrome a few thousand miles ago and after putting back together filled through top plug, no issue.
 
Thanks, that answers my first question. Now, will all oil drain out from the drain plug? I would assume that even if it didn't I could drain, refill, and repeat one or more times until the fluid is clear--then refill with the same amount originally drained. That might not be the best method, but if done every 10k it would be better than no change at all. Then at 50k do a disassemble and change it as per the book.
 
My bike had about 7500 miles on it when I put on the chrome lowers. The fork oil that drained out was sooo dirty, I don't think you could get it all out by removing just the plug at the bottom. What ever you end up doing, when you put in the new oil, use the heavier SE fork oil. It eliminates alot of the dive when braking.
 
I was planning on using the SE oil, or another 15W. I may try draining from the bottom and perhaps cycling new oil several times to clean it out by pumping the forks.
 
I've heard before that some of the dealers have a cool piece of apparatus that sucks the old fork oil out and replaces it with new through the drain hole. This sounds like a good way to go if there is such a thing. Anybody know for sure?
 
This works great on older bikes with air forks. I did this every 10k miles on my '96 RK and the entire job took about 20 min. I used a $10 venturi vacuum device from Harbor Freight Tools that connects to an air compressor to create a vacuum. Just plug it into the schrader valve (valve removed) to apply the vacuum.

I don't see an advantage to using this method with newer bikes, as you'd still need to remove the top plug to release the vacuum in the fork, and if it's already off you might as well install the new oil from the top. If you could seal the opening you could apply the vacuum from the top and suck it through the drain plug as with the older bikes, but again I see no advantage to going to the extra effort.
 
I ride an 07 ultra and this is the way I change fork oil.
1. Remove outer fairing.
2. Remove radio-to access top fork caps.
3. Remove top cap from one side.
4. Remove drain plug from that side and drain.
5. Slowly fill with oil from top and slowly work forks up and down until full.
6. Repeat for other side
 
I assume you mean by this that you fill from the top and slowing work forks up and down until filled with the specified amount (10.8 oz.) of oil.

BTW, you can access the top plugs by removing the ignition switch and fairing cap, which IMO is easier than removing the radio.
 
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