To Replace Fork Oil or Not...

[hppants]

I changed my fork seals and bushings about 20 months and 29K miles ago, re-filling the Honda 7wt. The forks are not leaking, no scratches what-so-ever on the upper fork tubes, I'm not having any front suspension problems, nor am I displeased in any way with bike performance.

Is there any benefit to replacing the fork fluid before changing seals, and if so, how often should it be done?

 

[majicmaker]

I think 29K isn't in the danger zone yet. Just don't wait til you hit 60K. I did and I had corrosion in one of them so bad that it had to be replaced. It wasn't cheap either!!! :-(

 

[leedavis]

I'd change it every 2 years as a maintenance cycle. Degradation in performance of fluids and lubrication points can sneak up on you because they occur so slowly. I don't know where it comes from but fork oil in particular seems to attract contamination.

 

[Fontanaman]

Dirty fork oil will contribute to the demise of the front fork bushings and contribute to corrosion. I upgraded my suspension at 30k miles, the bushing where shot and after reading some posts on this forum by member AuburnFJR I will be taking better care of my suspension with maintenance every 15 to 20k miles.

 

[Panman]

I change my fork oil every 10 or 12 thousand miles (usually when I changing out the tires, drain flush with a little kerosene and refill. I took my old ones that I changed out at 42,000showed them to the guy from GP suspensions at Auburns last tech day and he said he could put them back in. In 10,000 miles it's amazing just how cruddy that fluid gets.

 

[Queensland Ken]

I'd reckon every 20K, don't know where all the crud comes from, water, bushing material ???

A good idea to pop out and clean the dust seal as well.

 

[escapefjrtist]

I change my fork oil every 10 or 12 thousand miles (usually when I changing out the tires, drain flush with a little kerosene and refill. I took my old ones that I changed out at 42,000showed them to the guy from GP suspensions at Auburns last tech day and he said he could put them back in. In 10,000 miles it's amazing just how cruddy that fluid gets.

Gotta agree with Panman here...change the fork fluid annually for less wear and more consistent dampening action.

YMMV

--G

 

[Fred W]

I do believe in changing the fork oil at regular intervals. For me it has worked out to be around every 25-30k miles.

Where does the dark crud come from in the fork oil. It almost certainly has to be the teflon lining material they deposit on the wear surfaces of the bushings and, when that is gone, the bushings themselves. Nothing else is wearing on the inside of a fork.

As I reported in the "What did I do today" thread, when I disassembled by 1st gen forks at just shy of 80k miles, the bushings and seals were all still perfectly fine and serviceable. Surely the teflon coating on the old bushings was thinner than a new one, but it was not worn through yet, and the oil seals did not have any visible wear chamfered on the edges as compared to new ones.

Many, many 2nd gen owners report very different results at much lower mileages. I believe that this is due to the design change of having added a 3rd bushing in the second gen forks. Having three bushings means that any irregularity in the straightness of the inner fork legs will increase the friction applied on those bushings. Although the inner legs appear to be very straight and rigid, they will actually flex to some imperceptible extent during loading and unloading due to any force that is applied perpendicular to their travel.

Contrast that to my old bike, which I know has fork legs that are untrue (I noticed that the steering pulls unless the two are aligned a specific way, and I've gauged them on a flat surface when I had them disassembled) after having smacked a bambi about 40k miles ago. Yet with just two bushings inside them, the untrue forks will still slide perfectly well with no increase in stiction, and no apparent acceleration on wear. If I had (or ever buy) a second gen FJR the first time I serviced the forks I'd ditch the middle bushing.

Changing the oil is a pretty quick and relatively easy preventive maintenance any time you already have the front wheel off (you are more than half way there already.) But I would not recommend rebuilding the fork internals on a first gen unless/until you have an identified problem that needs to be fixed or you want to upgrade the hydraulic valving (which was the reason I disassembled mine)

As usual, YMMV

 

[hppants]

I would have thought that the majority of the crud in any fork is dirt/dust that gets past the dust seal and oil seal (not too difficult). All good advice, I guess. Next front tire removal, I'll go ahead and flush/fill the forks.

 

[BkerChuck]

For years Harley Davidson has listed fork oil change intervals on their bikes as a 10k interval item. They've just recently upped it to 20k. I have a vintage Honda where the owners manual calls for evey 6k. I haven't done the FJR yet but will likely do so when I change front tires. I work full time at a company that repairs hydraulic crane cylinders. A lot of fluid contamination we see comes from dirt and debris getting past the wiper which is what we call a fork seal on bikes. Some of the small flakes and debris in that oil is coming from the breakdown of the bushings in our forks.

 

[John d]

I change mine once a year whether is needs it or not. It looks like it needs it mostly. The first time was definitely the worst - break in wear I presume.

 

[FJRMGM]

well, at 95k miles the seals are really leaking on my '05 FJR. I changed the fluid every 30k or so.

Is there a write-up and parts list for items that need to be changed/replaced when I have them rebuilt?

thanks.

 

[Fred W]

well, at 95k miles the seals are really leaking on my '05 FJR. I changed the fluid every 30k or so.
Is there a write-up and parts list for items that need to be changed/replaced when I have them rebuilt?

Before doing that, I highly recommend using a seal mate (or home made version of one) and see if you can't get them to re-seat. The vast majority of leaky seals are caused by spooge getting stuck under the lip of the seal. Cleaning it out using the Sealmate trick can be done in minutes, with the forks still on the bike, and save a lot of effort if you have no other complaints about your fork action.

If you are dead set on rebuilding them, you'll want the oil seals and the upper and lower bushings. and of course 2 quarts of fork oil. Everything else can be reused. If you wanted to go whole hog you could also buy new dust seals. While you are putting the parts order in get the seal retainer clip too as it may be a bit crusty/rusty.

The job is pretty easy (especially on the 1st gens) for anyone with modest mechanical skills and a few tools.

 

[FJRMGM]

well, at 95k miles the seals are really leaking on my '05 FJR. I changed the fluid every 30k or so.
Is there a write-up and parts list for items that need to be changed/replaced when I have them rebuilt?

Before doing that, I highly recommend using a seal mate (or home made version of one) and see if you can't get them to re-seat. The vast majority of leaky seals are caused by spooge getting stuck under the lip of the seal. Cleaning it out using the Sealmate trick can be done in minutes, with the forks still on the bike, and save a lot of effort if you have no other complaints about your fork action.

If you are dead set on rebuilding them, you'll want the oil seals and the upper and lower bushings. and of course 2 quarts of fork oil. Everything else can be reused. If you wanted to go whole hog you could also buy new dust seals. While you are putting the parts order in get the seal retainer clip too as it may be a bit crusty/rusty.

The job is pretty easy (especially on the 1st gens) for anyone with modest mechanical skills and a few tools.

Fred, Just ordered a Motion Pro Seal mate from Amazon so will try that first and then change the oil.

thanks.

 

[Warpdrv]

My right fork was leaking and I picked up a seal mate - followed instructions from a you tube video, and worked perfectly as advertised.... 5 mins and no more leak.

With that said, its been a while since I installed the upgraded springs during the Wilburs Group Buy, but its an easy drain clean and fill.

well, at 95k miles the seals are really leaking on my '05 FJR. I changed the fluid every 30k or so.
Is there a write-up and parts list for items that need to be changed/replaced when I have them rebuilt?

Before doing that, I highly recommend using a seal mate (or home made version of one) and see if you can't get them to re-seat. The vast majority of leaky seals are caused by spooge getting stuck under the lip of the seal. Cleaning it out using the Sealmate trick can be done in minutes, with the forks still on the bike, and save a lot of effort if you have no other complaints about your fork action.

 

[FJRMGM]

well, at 95k miles the seals are really leaking on my '05 FJR. I changed the fluid every 30k or so.
Is there a write-up and parts list for items that need to be changed/replaced when I have them rebuilt?

Before doing that, I highly recommend using a seal mate (or home made version of one) and see if you can't get them to re-seat. The vast majority of leaky seals are caused by spooge getting stuck under the lip of the seal. Cleaning it out using the Sealmate trick can be done in minutes, with the forks still on the bike, and save a lot of effort if you have no other complaints about your fork action.

If you are dead set on rebuilding them, you'll want the oil seals and the upper and lower bushings. and of course 2 quarts of fork oil. Everything else can be reused. If you wanted to go whole hog you could also buy new dust seals. While you are putting the parts order in get the seal retainer clip too as it may be a bit crusty/rusty.

The job is pretty easy (especially on the 1st gens) for anyone with modest mechanical skills and a few tools.

Fred, Just ordered a Motion Pro Seal mate from Amazon so will try that first and then change the oil.

thanks.

used the Seal Mate and it fixed up my badly leaking left fork seal. Then I changed the fork oil to 10w Bel Ray and man I have a new bike suspension again!! The old oil was grungy and dark for sure! I will now change the fork oil every 20k religiously,

Thanks for the suggestion on the Seal Mate, mate!

 

[Fred W]

The only bad thing that one can say about the seal mate, or its ilk, is that it is taking money out of the pockets of motorcycle mechanics all over the world.

 

[FJRMGM]

The only bad thing that one can say about the seal mate, or its ilk, is that it is taking money out of the pockets of motorcycle mechanics all over the world.

LOL - yeah, for some reason they don't recommend using the Seal Mate.

I even talked to to local Yamaha dealer about replacing my seals before I used the Seal Mat and he was more that happy to get me on their appointment calendar!

I believe in replacing parts WHEN they need replacing..

 

[FJRay]

The only bad thing that one can say about the seal mate, or its ilk, is that it is taking money out of the pockets of motorcycle mechanics all over the world.

I'm in the other camp. I'm a m/c mech and I buy sealmates a dozen at a time and encourage my customers to use them. What they save on fork seals they end up spending on other service in the future. Gotta keep them coming back.