XJ Fork oil change question

[WSL91]

I'd like to flush the forks on the XJ1100. I've done this on other bikes which means drain the oil, pull the caps replace. The XJ has the air forks with the dampening adjustment knobs on the tops of the fork caps. What does one do to remove them or is there a different procedure with the XJ?
Thanks

[fredintoon]

I'd like to flush the forks on the XJ1100. I've done this on other bikes which means drain the oil, pull the caps replace. The XJ has the air forks with the dampening adjustment knobs on the tops of the fork caps. What does one do to remove them or is there a different procedure with the XJ?
Thanks

Hi John,
dunno if the XJ forks are different to my XS air-assist forks but it can't be too hard to do a routine maintenance thing like refilling them?
But what I'd suggest is you tear them right down and clean all the innards.
If that's never been done your forks have got 30 years-worth of crud inside them and that can't be a good thing.

[CatatonicBug]

Get yourself a manual. You can download one from the link in my signature. It will explain the process for you.

[WSL91]

I have the XJ service manual and it says to remove the cap (5-19 step 3). Anyone know how to do that? Do you just pry up gently? I get the overall strategy, just don't know how to remove the air adjust caps

[Rasputin]

Hi John,
dunno if the XJ forks are different to my XS air-assist forks but it can't be too hard to do a routine maintenance thing like refilling them?
But what I'd suggest is you tear them right down and clean all the innards.
If that's never been done your forks have got 30 years-worth of crud inside them and that can't be a good thing.

+1 on what Fred said. Every set I have taken apart has had mucho crud in them. I only change fork oil when I tear them apart and as it is a pain in the arse to do, I also change seals at that time. I figure that if I am spending the time that I may as well get it done the "better" way. Not to say that other methods do not work just my preference. I mean, like I am spending a few hours with one of my rides and sending a couple of beers to the happy hunting grounds so why not go all the way. Which also explains a few of the hangovers I have had by the way

[CatatonicBug]

The caps are screwed into the tops of the fork tubes. Loosen the fork tube clamps so they can slide easily (prop up the bike so it is not resting on the front wheel when you do this). Release all air pressure from the forks. Protect the fork caps with a heavy rag and use a pair of large channel locks to grip the cap on either side of the air fill valve. Unscrew the cap from the end of the tube (its the same diameter as the fork tube). If you need to, use the fork clamps to grip lower on the tubes (below the level of the threads, about 1.5" down) to gain some leverage.

I have the XJ service manual and it says to remove the cap (5-19 step 3). Anyone know how to do that? Do you just pry up gently? I get the overall strategy, just don't know how to remove the air adjust caps

[WSL91]

The caps are screwed into the tops of the fork tubes. Loosen the fork tube clamps so they can slide easily (prop up the bike so it is not resting on the front wheel when you do this). Release all air pressure from the forks. Protect the fork caps with a heavy rag and use a pair of large channel locks to grip the cap on either side of the air fill valve. Unscrew the cap from the end of the tube (its the same diameter as the fork tube). If you need to, use the fork clamps to grip lower on the tubes (below the level of the threads, about 1.5" down) to gain some leverage.

I'm up on the steel fork tube caps unscrew from the fork tubes, I'm asking about the PLASTIC dampening adjusters that have a range of 1-4. Step 3 of the manual refers to removing the PLASTIC caps, further down in the instructions they remove the STEEL caps.
Thanks

[WSL91]

+1 on what Fred said. Every set I have taken apart has had mucho crud in them. I only change fork oil when I tear them apart and as it is a pain in the arse to do, I also change seals at that time. I figure that if I am spending the time that I may as well get it done the "better" way. Not to say that other methods do not work just my preference. I mean, like I am spending a few hours with one of my rides and sending a couple of beers to the happy hunting grounds so why not go all the way. Which also explains a few of the hangovers I have had by the way

SO how do you remove the PLASTIC dampening adjusters prior to unscrewing the metal fork caps?

[natemoen]

If it is like the XS, it is just a push on rubber protective cap. Just pry it up.

[WSL91]

If it is like the XS, it is just a push on rubber protective cap. Just pry it up.

Unfortunately they're not, its a hard plastic dial with 5 positions. Apparently there are long rods coming up from the within the forks attached to them from the back. The manual says to remove them but doesn't say how, surely someone here with an XJ has pulled them. I'm going to go out and look at them again and try gently prying up, maybe they are just pressed onto the rods for the dampening adjustment. The item that the red arrow is pointing at is what I'm asking about
Thanks
John

[Yahman]

Use a socket or a wrench to get on the metal nut part of the cap, right below the plastic dampening adjuster, that the arrow is pointing to. Do not pry on that adjuster or it will be garbage. As was mentioned, loosen the top triple clamps first. The complete cap assembly should unscrew from the tube.

Larry

[WSL91]

Use a socket or a wrench to get on the metal nut part of the cap, right below the plastic dampening adjuster, that the arrow is pointing to. Do not pry on that adjuster or it will be garbage. As was mentioned, loosen the top triple clamps first. The complete cap assembly should unscrew from the tube.

Larry

Thank you sir, I tried prying them off with light to moderate force and they didn't move so I stopped. In my younger years I would have just applied more force

[crazy steve]

I think Larry's got it; I need to do the same thing on my XJ (but I need to get the motor back together first), but the FJ forks I'm using on one of my other XS's had the same deal and the adjustors come out with the cap....

[XJkid]

Just loosen the metal nut. It's all one unit. The plastic adjuster knob comes with it. Just be careful with the long skinny rod that comes out with it. One of mine was bent a little, but I CAREFULLY bent it back. They seem to be pretty fragile and trying to bend one back could go wrong fast. Also, notice that this rod has sort of a half-moon cross section. When you reassemble it, make sure that the rod end drops down into the corresponding half-moon slot in the fork. Otherwise you could bend it pretty bad. These manuals are not always quite clear on how to do something, they just tell you to do it. I tried to get a look at my seals, but my snap ring tool was too wimpy to pull it out, so I left well enough alone. They weren't leaking so I'll worry about that another time.

[WSL91]

Just loosen the metal nut. It's all one unit. The plastic adjuster knob comes with it. Just be careful with the long skinny rod that comes out with it. One of mine was bent a little, but I CAREFULLY bent it back. They seem to be pretty fragile and trying to bend one back could go wrong fast. Also, notice that this rod has sort of a half-moon cross section. When you reassemble it, make sure that the rod end drops down into the corresponding half-moon slot in the fork. Otherwise you could bend it pretty bad. These manuals are not always quite clear on how to do something, they just tell you to do it. I tried to get a look at my seals, but my snap ring tool was too wimpy to pull it out, so I left well enough alone. They weren't leaking so I'll worry about that another time.

Thanks for the advice. I figured out that they rotated 360 and kept going so I was wondering if they came off with the steel caps. Tomorrow is the day now. I have located the right size socket and everything is soaking today with penetrating oil. I too have learned to not fix what isn't broke but it took me a while. I intend to photograph everything and put together a thread so someone can search next time and see pix. I'll probably post it on my website too. I photographed a Master Cylinder teardown and reassembly but haven't posted yet. It will be part of my thread for de-linking the brakes on the XJ including hooking both front rotors to the front M/C. Eliminates the problem prone proportioning valve.